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 inflator mechanism for a dry suit. Easy to install on standard hoses placed between the hose and the second stage regulator or between the first stage regulator and power inflator hose 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 9/16-18 UNF Male Inlet to 9/16-18 UNF Female Outlet Threads. Inline Shut-Off is commonly used with Deco Rigs, Stage Bottles & Dry Suit Inflation 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.