Developed for shooters who value predictable performance during regular practice, the Troy Ind STRXAL190BT01 Alpha Rail Aluminum Black Anodized 9" for AR-15, M16 offers practical handling.\n\nThis genesis of modular free-float rails has arrived, building off the TRX Extreme design. The Alpha Rail utilizes a low-profile locking mechanism which offers unparalleled strength and stability. The Alpha Rail disperses heat and runs cooler than other close-to-the-barrel rail systems. With unlimited mounting options and greater heat dispersion, the Alpha Railsets comes with three detachable rails and all mounting hardware. Works with standard AR15/M16 barrel nut (no barrel nut included). Includes two 2" and one 4.2" detachable rails and all mounting hardware. Note: Alpha rails do not work with the TRX barrel nut or wrench.\n\n- Manufacturer: Troy Industries\n- Model: STRXAL190BT01\n- Product Type: Railed Forend\n- Mounting System: Proprietary\n- Material: Aluminum\n- Unique Features: 8 Angles Of Attachment, 1 Fixed/3 Detachable Rails\n- What's In The Box: Two 2" and one 4.2" detachable rails, all mounting hardware