Color-coded for gas service to provide added safety. Internal check valves designed to prevent reverse flow and accidental mixing of oxygen and fuel gases. Torch and regulator models provide downstream and upstream protection. 10" maximum cutting capacity. For stopping flashbacks by preventing ignition of mixed gases and to protect equipment such as hoses, regulators, and cylinders. Size: 9/16 in - 18 tpi; B-Size; Material(s): Brass; For Use With: Oxygen/Fuel Gas Lines.