The Troy Industries Delta Battlerail is a free-float drop in rail that installs easily. The Delta rail is a two-piece customizable rail designed for rifles with a carbine length gas system. The rail has a cut-out to accommodate the standard front sight. There are two push button quick detach sling sockets located on the left and right sides of the rail at the front sight location. The rail system has a built in top rail section and a short rail section underneath the front sight post, with the option to add customizable rail sections (sold separately) where needed to accomodate the shooter's choice of tactical accessories. Installation of the rail does not require the removal of the barrel nut, delta ring, or front sight. The Delta rail will give you more room to mount foregrips, lights and other accessories than the standard drop-in carbine rails, and does not require specialized tools to disassemble the upper or an upgraded gas block to gain the extra rail space.