This Vltor A5 Recoil System AR-15 Receiver Extension Tube is an improved buffer tube design that features 7 different positions to provide the ultimate in stock adjustability. The tube's Shortest Length of Pull position is as compact as a fully collapsed M4 Carbine Buttstock while its Longest 7th Position stretches stock length to slightly longer than that of an M16A2 Fixed Stock. Manufactured from Impact Extruded 7075-T6 Aluminum and given a durable Hard Anodized Finish, the A5 Buffer Tube is compatible with Mil-Spec Diameter, Lengthened Collapsible Stocks such as the Vltor EMOD. The Vltor A5 Recoil System was developed at the request of the US Marine Corps as a potential future upgrade to replace the current A2 Fixed Stock used on the M16A4. The new recoil system consists of the Longer A5 Receiver Extension Tube with 7-Positions, a Longer and Specially Weighted A5 Buffer, and a standard Rifle Length Buffer Spring. The A5's enhancements to the AR-15 operating system result in a rif...