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 first 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 Ribbed Texture makes it easy to operate even when wearing gloves. Inline Shut-Off has 3/8-24 UNF Male Inlet to 3/8-24 UNF Female Outlet Threads. Inline Shut-Off is commonly used with Deco 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 really 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.