The Battle Arms Development's Vert Stock System-PDW Stock is M16 BCG compatible with no proprietary bolt carrier group required. It offers a continuous cheek rest for stable shooting" ultra-compact buffer and buffer spring" four locking stock positions and two QD sling swivel points. The system is designed for 5.56/.223 direct gas impingement systems and will also work on 300BLK DI systems as well but must have appropriate gas port size. Will not work with solid filled 9mm bolt carrier.The inside" rear cavity of the bolt carrier must be .625" in diameter x .625" deep minimum to clear the buffer. The system should be configured" installed and function checked by a qualified gunsmith for reliable and safe operation.

Features :

• "Fully Collapsed Length = 4.75" (Not longer 5.5" /- PDW Style Stocks)"
• "Fully Extended Length = 8.75";"Lightweight 19.5 Ounces"