The HydraStorm GMAK is a true gas mask adapter kit for the professional. The fittings each feature military configuration sealing valves to prevent ingres of contamination into your water supply and your mask. The valves only open when the mating parts are correctly aligned and pressed together. When disconnected your water supply remains protected. The GMAK connections will open the water supply only when fitted to the gas mask drinking tube or the bite valve adapter supplied, otherwise the integral valves block the water path for safety. No leaks out and no contamination in. The StormLock bite valve and an auxilary external shut off for use when connected to your mask are provided to lock off flow for full flexibility use. The materials and/or components selected for the GMAK are all in service with the US and Canadian forces for handling portable water. The interface geometry for the transfer of water from the HydraStorm reservoir to the user's protective mask is the same as used in the US and Canadian military NBC systems. GMAK includes: Complete tube kit, ready to go. Easy screw on-off to HydraStorm reservoir. Universal adapter for NATO standard gas mask drinking tube. Fits the M40, C4, S10, Millenium among others. Bite valve with StormLock. Additional tube shut off for use when connected to the mask. NyTaneon tube cover to prevent excess exposure. OC-CS environments.