that's a lyman model sml peepsight for t/c hawken, lyman trade rifle, deerstalker & similar guns. I have one on my hawken &although it's a bit bulky it works great. much finer & more controllable adjustments possible than with the t/c sight. ya can't really see it in the pik but it has two holes for mountin' on t/c tang in same manner as thompson's peepsight. and if ya want to use it on a renegade ya have to carve a little notch in the stock or use a spacer of some kind. to use the contender sight you'd likely have to manufacture some type of sight to tang adapter. luck & have a good'en friend, bubba.
