this invention gets below the hard surface of a cantaloupe or other fruits in order to gauge the degree of ripeness / softness . it does this without the need to cut open the fruit . this tool breaks the surface of a fruit with a small hole of about one millimeter in width , so the fruit can continue to ripen if need be . the invention looks like the body of a simple ball - point pen with a wire probe coming out of the pointed end . the visible part of the wire probe is immersed into the fruit , and if the fruit is hard and not ripe , the spring inside the invention will compress during this immersion and when the body is released , the degree to which the body of the invention springs back , is determined by degree of spring compression and the hardness of the fruit and thereby its ripeness . the harder the inside of the fruit , the more the spring compresses and the more the body of the invention springs back . ( see diagrams 2 / 3 and 3 / 3 ) this hardness / ripeness gauging is achieved in a fairly simple , consistent and measurable manner with the use of a spring inside the body of the invention , which compacts when the wire probe is pushed into hard fruit . an un - ripened hard fruit provides resistance , causing the spring to compress when the probe is pushed inwards . when the body of the invention is released , the compressed spring forces the body of the invention away from the fruit . in contrast , when the wire probe is pushed into soft / ripe fruit there is little resistance and the spring does not compress , resulting in very little if any spring back when the operator releases the body of the invention . users will easily get accustomed to how much spring back is personally desired before cutting or biting into the fruit . the invention consists of a capped tube with a 16 gauge stainless steel food grade wire probe protruding from one end . the remainder of the wire probe is inside the tube along with a spacer and a spring . ( see diagram 3 / 3 ) the spacer ( or filler piece ) is needed between the spring and the probe so that they do not intertwine . to build this invention you need a capped tube , such as the housing for a simple ball - point pen , a spring rated between 2 and 3 pounds per inch that fits inside the pen tube , a spacer that slides easily within the tube and a piece of 16 gauge awg stainless steel wire to use as the probe . the wire is bent over at the end that butts up to the filler piece which helps position the wire probe and prevents it from falling out of and away from the body of the invention . the length of the wire probe is such that when the wire probe is pushed as far as it can go into the tube , against the spring , approximately half to one inch of the wire probe would be protruding from the narrow end , which enables the operator to push through the hard outer skin of a cantaloupe or melon .