Very sturdy clamp for intercooler piping, silicone hoses and exhaust systems. olt 63-68mm Hose Clamp with M8 Bolt The strongest clamps for charge air ducts Thanks to the M8 bolt these clamps can be extremely tightened. The clamps can be used for exhaust system as well. The strongest clamp available for charge air ducts. Material : zinced steel Size : 63mm up 68mm Band Width: 20 mm Please keep in mind that silicone hoses are always measured by inner diameter. To get the correct clamp size add 8 - 10mm to the silicone hose inner diameter!