Super Quick Fist is ideal for holding fire extinguishers, oxygen cylinders, CO2 tanks, and other equipment with a diameter measuring 2-1/2" to 7-1/2". Perfect for boaters who need to keep chart tubes handy. Clamp mounts easily with three #10 (5 mm) bolts or screws (not included). Can be mounted with strap facing any direction and then trimmed off for neat installation. Each clamp supports approximately 50 lbs. Mounting base measures 7/8" x 6".