Super Quick Fist Clamp. Super Quick Fist is ideal for holding fire extinguishers, oxygen cylinders, CO2 tanks, and other equipment. Mounts easily with three #10 (5 mm) bolts or screws (not included). Can be mounted with strap facing any direction.. Specifications:. Holds objects from 2-1/2 to 7-1/2" in diameter (64 to 191mm). Each clamp supports approximately 50lbs (23 kg). Mounting base measures 7/8 x 6" (22 x 152 mm). Typical uses:. Mount a large fire extinguisher with Super Quick Fist. Super Quick Fist neatly stores chart holders. Super Quick Fist affixes a D-size oxygen cylinder. Two Super Quick Fists hold a 7" CO2 tank