Buy Nilight 2PCS Roll Bar Clamps Mounting Brackets. The roll bar clamp is designed to mount led lights on bigger horizontal tube sizes, 2.135 inches, 2.25 inches, 2.375 inches, and 2.5 inches. And it is applicable for bull bars roll cages or any round bar on motorcycles, bicycles, ATVs, UTVs, boats, JEEP, and trucks.