The tool has sockets for 1/2" and 3/4" gas valves. My gas valve is slightly larger than 1/2" (maybe 5/8" by PG&E in California) and the 3/4" socket was way to big to close the gas valve. So, check the size of your gas shut off valve first before buying this tool. The tool looks OK for 1/2" and 3/4' valves