Oetiker® Stepless® Self-Compensating Constant Tension Clamps are specifically developed to permanently stop cold leaks with black EPDM or soft silicone coolant system hoses on diesel or other engines. Their narrower band width & precise tongue-in-groove stepless interior, coupled with a low installation torque, achieves a strong uniform 360º seal. The preloaded spring tension effectively compensates for common coolant leakage during thermal cycle changes.