TROY Industries Swivel, Fits TRX Rails, Quick Detach, Black Finish SRAI-TRX-HERP-00 The Low Profile Q.D. Sling Mount is a low profile" lightweight and durable S.S.Q.D. sling mount solution for Alpha" Alpha .308 TRX Extreme" TRX .308 Rails and T-22 Sport Chassis. Not compatible with the Alpha Revolution Rail. Includes S.S.Q.D. Swivel.