Uniweld 70022 Reversible Ratchet Wrench with DHVA Dual Hex Wrench Adaptor Square opening with 1/4in and 3/16in at one end; 3/8in and 5/16in at the other For use on compressor access valves and acetylene B and MC tank valves Includes Uniweld's DHVA Dual Hex Wrench Adaptor for use on 3/16" and 5/16" hex liquid and suction line valves