First one and i like it! - Precision Reflex AR-15/M16 Round Free Float Carbon Fiber Extended Forearm

First off just get the wrench for the handguard lug and the pri barrel nut wrench. Secondly it will add a little weight but its sturdy as h e dbl hockey sticks... This round version wont accept the superlative low pro piston system the delta does... you want solid lock up and something good for a clipon thermal use med. Height rings on your scope itll line up perfect...