I took my Allegiance to have one installed last weekend and it would not work. At least they said it wouldn't and I went with the Trophy Taker Shakey Hunter rest instead. I'm not sure they won't work or if they just got tired of fooling w/ it. The TT went on without a hitch though. They tried to tie it into the cables but ended up just attaching it to the cable slide because they said there was to much movement in the cables. I did notice that on the Cobra the built in arrow holder isn't much. I think you would be smart to still install a NAP arrow holder in front of it. Just my experience but I'm no technical guru.