Comcast user in ca . run a cable modem and a hd box off 1 co-ax in -lrb- set-up be cable in - to junction box - to cable modem out and cable box from tap -rrb- . I be have issue with several hd channel and I want to add another line so I could have 2 cable feed on my 60 '' screen -lrb- as in watch 2 football game -- yup -rrb- . I get this box -lrb- install before the junction box -rrb- along with the Audiovox dh24spr two way 2.4 Ghz Bi-Di Splitter -lrb- install on the co-ax from the tap - then to cable box + tv in -rrb- . result -- endzone ! the mess up channel be back on my hd box , my internet be just as crazy fast as it be before -lrb- maybe - maybe faster -rrb- , and I now can watch two channel at once on my tv with split screen . I be a techie guy and research everything well before buy , and this one be a hit . I recommend .