TheDiversitech Cop Cap Locking Valve Cover is an effective way to discourage and prevent the removal of refrigerant. COP-CAP™ fits this standard service valve on all central AC units and mini-splits. It helps prevent access by unauthorized persons and can only be removed with the included special tool. Simply thread COP-CAP™ assembly onto existing 1/4in. flare connection on system and lock set screw in place with hex wrench provided.