Our European style worm gear clamps are a non-perforated clamp that are made for fuel, vacuum, water, emission and heater hoses as well as silicone hose due to their non-perforated smooth band. They feature either an 8MM or 9MM wide 300 stainless steel band depending on the size, a 300 stainless steel housing, and a 6mm zinc plated steel screw. The unique off-set housing design provides some resistance to over-tightening, preventing hose damage.