This protective cap has been designed to make it obvious when a compressed gas cylinder has been used.  The protective cap must be destroyed during removal.  It cannot be taken off and put back on.  This prevents tank mix-ups in cages where someone removes the cap from a full cylinder, puts the cap on the empty cylinder, and returns it for exchange.  The next person sees a cap on the cylinder and assumes it is full, and carries home an empty cylinder.  A broken strap means the tank has been used.  This cap is Orange in color.  It can be used on a variety of compressed gas valves including CGA 500, 510, 580, and 590.  Other colors are availabe.  ACM-607 (Blue); ACM-608 (Gray); ACM-609 (Natural); ACM-610 (Orange); ACM-611 (Yellow).  Note:  THIS CAP WILL NOT WORK ON OPD STYLE PROPANE VALVES.