Shotgun Tri-rail barrel mount: 1.Three Universal Rails, 3 Slots Each Rail 2.Easy To Install 3.Hard-coat Anodized Finish MTS0016 Shotgun Tri-rail barrel mount1) Three Universal Rails, 3 Slots Each Rail 2) Fits Barrel Dia. Up To 26mm 3) Lower Portion Fits Laser/Flashlight Dia. Up to 1" 4) Easy To Install 5) Hard-coat Anodized Finish 6) Made by Premium Aircraft Grade 6061 Aluminum