Mishimoto's Constant Tension T-bolt Clamps are the ideal choice for clamping hoses and couplers that see a wide range of temperature and where high clamping force is needed. This 3.11in - 3.43in (79mm - 87mm) constant tension T-bolt clamps takes the superior clamping force of our traditional T-bolt clamp and adds even more reliability. A spring on the adjustment bolt allows the clamp to expand and contract with temperature swings while keeping constant pressure on the clamped parts. Like our traditional T-bolt clamps, these constant tension T-bolt clamps include a locking nut to prevent loosening under vibration.Like all Mishimoto clamps, this 3.11in - 3.43in (79mm - 87mm) constant tension T-bolt clamp is backed by our Mishimoto Lifetime Warranty.