Strike Industries AR Pistol Flat Wire Spring, 10 in, Black, One Size, SI-AR-FWS-P, Black, One Size, SI-AR-FWS-P

"Strike Industries AR Pistol Flat Wire Spring, 10 in, Black, One Size, SI-AR-FWS-P, Black, One Size, SI-AR-FWS-P. The Flat Wire Spring design packs more energy than traditional round wire springs giving it increased bolt power.