The LT-724 was initially designed to fit on the upper receiver in front of a Trijicon ACOG without the need for a railed handguard (note: a standard rear BUIS may not fit with the LT100 and LT724 combination). The LT-724 is also widely-used on free float and continuous-railed handguards in combination with any scope with side turrets shallower than ½" in length, like Trijicon Accupoints, Burris XTR, Leupold CQ/T, Leupold Mark 4 w/ M2 turrets, etc. (Note: The LT724 will not fit underneath our cantilever mount's forward extension)