This Double Shotgun Barrel Mount Tri-Rail System features 3 sections. The 3 piece design is for clamping onto shotgun/paintball Gun barrels and Tube. Specifications: Compatible Firearm Barrel Range: Diameter.75 Inch-1.1 Inches; Tube Clamping Range: .75 Inch-1 Inch; Rail Type: Picatinny/Weaver; Body Material: Aluminum; Weight: 3.7 oz; Length: 3.5 Inches x 2.75 Inches x 2.25 Inches; Included Accessories: Allen Wrench and Set of 0.7 Inch Screws; Warranty: 1 Year Limited