Troy's revolutionary new free float two-piece modular and quad rail drop in rail system requires no Gunsmithing to install, requires no modification to the firearm, has two built in Q.D swivel mounts, and free floats the barrel for improved accuracy. This two-piece rail system installs in minutes and offers and extended forearm while allowing the user to keep the existing fixed front sight post. The Delta modular rail system also allows the user to add smaller rail segments (Included) to the rail where needed without having the added weight of a full-length quad system. Troy's new drop-in free-float rails are built off a rock solid rotary clamping system; do not require removal of the delta ring, barrel nut or fixed front sight. Troy's new Drop-in free float rails are the easiest to install, and most versatile free float system available on the market. Made in the U.S.A.