T-bolt clamps are designed to assure proper coupling retention for any marine hose. They offer a full 360 clamping surface, ideal for any below water line connection. Series 720 clamps have a 3/4" wide 301 stainless steel band with a 1/4" 18-8 stainless steel bolt and nylon insert lock nut. Torque to 75 inch-pounds maximum. The 720 Series clamps come in two size ranges: L (Long) and HT (Hi-Temp) L Series clamps are sized for thicker walled, black rubber water/exhaust hose HT Series clamps are sized for thinner walled, blue silicone exhaust hose