the following description is of the best presently contemplated mode of carrying out the present invention . this description is not to be taken in a limiting sense but is made merely for the purpose of describing the general principles of the invention . the scope of the invention should be determined by referencing the appended claims . fig1 shows a perspective view of a guide piece of the present invention . referring now to fig1 guide piece 10 is comprised of an elongated body 12 with a u - shaped channel 18 extending down the entire length of elongated body 12 forming end openings 16 on either end . in the preferred embodiment the end openings 16 are beveled at an approximate angle of 9 . 46 ° to allow for easier insertion of an edge of an electronic circuit card . an outer surface 20 extends down the length of one leg of u - shaped channel 18 . a plurality of raised tabs 14 are located along and molded into outer surface 20 . one skilled in the art will recognize that in addition to being molded into the guide piece , the raised tabs 14 could also be attached or affixed to external surface 20 of elongated body 12 with glue or adhesive . raised tabs 14 are l - shaped with one leg of the l oriented parallel to outer surface 20 and extending towards u - shaped channel 18 and the other leg of the l extending substantially perpendicular to outer surface 20 . in the preferred embodiment , each leg of raised tabs 14 has a flat surface whose side edges are beveled downward at an angle from the flat surface ( as more fully shown in fig1 ), to allow for easier mating when attaching guide piece 10 to a chassis ( not shown in fig1 ). the one leg of the l oriented parallel to outer surface 20 has side edges beveled downward at an approximate angle of 18 . 43 °. the other leg of the l extending substantially perpendicular to outer surface 20 has side edges beveled downward at an approximate angle of 25 . 0 °. fig2 shows another perspective view of guide piece 10 . referring now to fig2 an outer surface 26 extends down the length of the other leg of u - shaped channel 18 . a plurality of middle nubs 22 are located between the ends of outer surface 26 . in the preferred embodiment , the middle nubs 22 are beveled at an approximate angle of 16 . 36 ° in the direction towards u - shaped channel 18 ( as more fully shown in fig1 ) to aid installation . also located on outer surface 26 at each end are end nubs 24 . in the preferred embodiment , the end nubs 24 are beveled at an approximate angle of 18 . 45 ° in the direction towards the end of the guide piece 10 ( as more fully shown in fig1 ) to aid in removal of the guide piece . one skilled in the art will recognize that in addition to being molded into the form , middle nubs 22 and end nubs 24 could also be attached or affixed to external surface 26 of elongated body 12 with glue or adhesive . fig3 shows a perspective view of the inside corner of a typical chassis 34 . referring now to fig3 end nub holes 30 are cut out from bottom 31 of chassis 34 for receiving end nubs 24 . middle nub holes 28 are cut out from bottom 31 of chassis 34 for receiving middle nubs 22 . middle nub holes 28 may also be sized only slightly larger than middle nubs 22 . fingers 32 are formed in adjacent side 33 of chassis 34 for mating with raised tabs 14 . referring now to fig4 guide piece 10 is shown attached to chassis 34 shown in fig3 . attaching guide piece 10 in this orientation , wherein u - shaped channel 18 faces horizontally with respect to bottom 31 of chassis 34 , comprises positioning guide piece 10 so that outer surface 26 faces down , outer surface 20 faces up , and u - shaped channel 18 faces horizontally away from adjacent side 33 of chassis 34 . guide piece 10 is placed flush with adjacent side 33 and bottom 31 of chassis 34 with raised tabs 14 on one side of fingers 32 . another way to describe this is to position guide piece 10 such that raised tabs 14 are beside and offset to fingers 32 . guide piece 10 is then moved laterally to orient raised tabs 14 under and behind fingers 32 . fig5 shows a cross section of guide piece 10 being attached to chassis 34 in the horizontal orientation shown in fig4 . guide piece 10 is positioned flush against adjacent side 33 and bottom 31 of chassis 34 and moved laterally in the direction indicated by directional arrow 35 . one skilled in the art will recognize that for installation guide piece 10 may also be positioned with raised tabs 14 on the opposite side of fingers 32 as shown in fig5 and moved in a lateral direction opposite to that indicted by directional arrow 35 . as raised tabs 14 begin contact along their beveled edges with fingers 32 , the middle portion of guide piece 10 is forced down , flexing guide piece 10 into a mild bow shape , and middle nubs 22 begin to seat in middle nub holes 28 . end nubs 23 and 24 are still resting on the upper surface of bottom 31 of chassis 34 . as guide piece 10 is further moved laterally in the direction indicated by directional arrow 35 , end nubs 23 and 24 seat into end nub holes 29 and 30 , snapping down into place due to the tension in the flexed guide piece 10 . snapping into place relieves the flexed bow shape of guide piece 10 and raised tabs 14 become fully mated with fingers 32 , and middle nubs 22 and end nubs 23 and 24 fully seat with middle nub holes 28 and end nub holes 29 and 30 respectively . to remove guide piece 10 from chassis 34 from the horizontal orientation shown in fig4 and fig5 front end 27 of guide piece 10 is lifted vertically to allow end nub 24 to clear end nub hole 30 . after being lifted , guide piece 10 is moved laterally in the opposite direction indicated by directional arrow 35 of fig5 . as guide piece 10 is lifted and moved , trailing end 25 of guide piece 10 slides along the beveled surface of end nub 23 up and out of end nub hole 29 . when raised tabs 14 pass completely from behind and under fingers 32 , guide piece 10 may then be fully removed from chassis 34 . referring now to fig6 guide piece 10 is shown attached to chassis 37 in a corner offset in a horizontal orientation . raised tabs 14 are mated with fingers 39 formed in the corner offset . middle nubs 22 and end nubs 24 are seated respectively in middle nub holes 28 and end nub holes 30 ( not shown ). guide piece 10 is attached and removed in this corner offset position in the same manner as described above with respect to fig5 . referring now to fig7 guide piece 10 is shown attached to chassis 41 in an interior location with a vertical orientation wherein u - shaped channel 18 faces up . raised tabs 14 are mated with fingers 43 formed in bottom 42 of chassis 41 . referring now to fig8 guide piece 10 as shown in fig7 is shown in a perspective view from the opposite side . a plurality of c - brackets 36 are formed in bottom 42 of chassis 41 wherein each c - bracket will seat with a middle nub 22 . o - shaped brackets 38 are formed in bottom 42 of chassis 41 wherein each o - shaped bracket will seat with an end nub 24 . guide piece 10 is attached and removed in this interior location with a vertical orientation in much the same manner as described above . referring now to fig9 guide piece 10 is attached to chassis 44 in an interior location with a horizontal orientation . raised tabs 14 are mated with a plurality of slotted brackets 40 formed in bottom 45 of chassis 44 leaving cut outs 47 . middle nubs 22 and end nubs 24 are seated respectively in middle nub holes 28 and end nub holes 30 ( not shown ). attaching guide piece 10 in this interior location comprises positioning guide piece 10 in a slightly rotated orientation so that outer surface 26 faces generally toward , but is not parallel to bottom 45 , outer surface 20 faces generally away from bottom 45 , and u - shaped channel 18 faces generally horizontally away from slotted brackets 40 . guide piece 10 is positioned so that the tops of raised tabs 14 pass under the forward portions 46 of slotted brackets 40 and engage in the wider portions 48 of slots 50 . guide piece 10 is then rotated so that the extended legs of raised tabs 14 become vertical with respect to bottom 45 of chassis 44 , and outer surface 26 becomes horizontal with respect to bottom 45 of chassis 44 , resting upon end nubs 24 with middle nubs 22 positioned above middle nub holes 28 ( not shown ). middle nubs 22 aid in this rotation process due to their beveled surfaces that contact with bottom 45 of chassis 44 . guide piece 10 is then moved laterally in the direction indicated by directional arrow 52 . as the beveled portions of both legs of raised tabs 14 come in contact with the narrower portions 54 of slots 50 in slotted brackets 40 , the middle portion of guide piece 10 is forced down , flexing guide piece 10 into a mild bow shape , and middle nubs 22 begin seating in middle nub holes 28 ( not shown ). end nubs 24 ( not shown ) are still resting on the upper surface of bottom 45 of chassis 44 . as guide piece 10 is further moved laterally in the direction indicated by directional arrow 52 , end nubs 24 seat in end nub holes 30 ( not shown ), snapping down into place due to the tension of the flexed guide piece 10 . snapping into place relieves the flexed bow shape of guide piece 10 and raised tabs 14 become fully mated with slotted brackets 40 and middle nubs 22 and end nubs 24 become fully seated respectively with middle nub holes 28 and end nub holes 30 ( not shown ). to remove guide piece 10 from chassis 44 from the horizontal orientation shown in fig9 front end 56 of guide piece 10 is lifted vertically to allow end nub 24 to clear end nub hole 30 ( not shown ). after being lifted , guide piece 10 is moved laterally in the opposite direction from directional arrow 52 . as guide piece 10 is lifted and moved , trailing end 58 of guide piece 10 slides along the beveled surface of end nub 24 up and out of end nub hole 30 ( not shown ). when raised tabs 14 pass into wider portion 48 of slots so of slotted brackets 40 , guide piece 10 is then rotated in the opposite direction from installation . as raised tabs 14 pass below and away from forward portions 46 of slotted brackets 40 , guide piece 10 may then be fully removed from chassis 44 . the method of installation and removal as described above in reference to fig9 may also be used in installation and removal in reference to fig4 and fig5 fig6 and fig7 and fig8 . however , this rotation method in reference to fig9 is not as optimal as the methods previously described for these other orientations in fig4 through fig8 . referring now to fig1 , a portion of guide piece 10 is shown wherein raised tab 14 , located on outer surface 20 , has two flat surfaces 60 on the interior side of each raised tab leg adjacent and perpendicular to each other . extending out from each flat surface 60 are exterior beveled edges 62 which aid installation by allowing raised tabs 14 to slide along the beveled edges 62 against fingers 32 ( not shown in fig1 ) to seat on flat surfaces 60 . referring now to fig1 , a portion of guide piece 10 is shown wherein end nub 24 , located on outer surface 26 , has a beveled top surface 68 angled away from outer surface 26 in a same direction as a long dimension of guide piece 10 . one skilled in the art will recognize that the orientation of end nub 24 may be reversed , requiring opposite lateral movements from those described above for installation and removal of guide piece 10 from a chassis . referring now to fig1 , a portion of guide piece 10 is shown wherein middle nub 22 , located on outer surface 26 , has a beveled top surface 64 angled away from outer surface 26 forming a side of longest dimension 66 that is perpendicular to outer surface 26 and faces towards u - shaped channel 18 . having described a presently preferred embodiment of the present invention , it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the present invention , as defined in the claims . the disclosures and the description herein are intended to be illustrative and are not in any sense limiting of the invention , defined in scope by the following claims .