Highland by XS Scuba's Inline Shut-Off is an inline valve that can be used for closing off the air flow to your second stage regulator or re-breather. Easy to install on standard hoses placed between the hose and the second stage regulator for quick and easy shut-off of air or to allow air flow to continue. Just slide the knurled slide collar to shut-off or turn-on gas flow. Slide is made from durable machined Delrin and the knurled texture makes it easy to operate even when wearing gloves. Inline shut-off has 9/16-18 UNF male inlet to 9/16-18 UNF female outlet threads. Inline shut-off is commonly used with decompression rigs, stage bottles and re-breathers and can prevent critical gas loss due to cold water diving, free-flow caused when entering water through surf or off the back of a boat. Inline shut-off will also stop on wanted free-flow caused by currents, which is handy with deco-rigs or stage bottles that may be left unattended at decompression and safety stops. Inline shut-off is for use with low pressure only below 200 psi (13.8 bars). Threaded couplings are made from marine grade brass for strength and durability.