The amazingly versatile TRM3 Three Rail Mounting System fits most AR15/M16 handguards to allow for easy tactical light operation while using a vertical grip and light mount. The 45º rails can be used independently of each other and won't interfere with iron sights. Mounts fit on most upper and lower existing thermal handguards. Constructed of durable high-density polymer. No gunsmithing required to install or remove. Unconditional lifetime warranty.