The patented two chamber hydration reservoir (THE GEIGERRIG HYDRATION ENGINE) hosted exclusively by GEIGERRIG, has several key components that provide key benefits for any hydration pack user. GEIGERRIG hydration bladders are compatible with most other packs. The slide top allows the entire top of the reservoir to open up to provide easy access for cleaning, drying and filling. This slide top is a key product component that comes from our healthy relationship with the company Hydrapak. The quick release valves allow you to easily disconnect the tubes and leave them positioned in the hydration pack while you remove the reservoir for filling and cleaning. The bite/pinch valve has an on-off switch as well as a special configuration that makes it uniquely suitable for pressurized, spray hydration without leakage. This Surge Protector valve is a great product benefit that comes from our healthy relationship with the company Hydrapak. The pressure bulb and pressure tube provides the mechanism to pressurize our hydration bladders utilizing the patented two chamber system. Spray to drink, Spray to Cool, Spray to Clean, Spray to Share...etc. It is certainly convenient to have this capability so that you can enjoy these benefits from the hydration pack on your back. Dishwasher safe, and BPA free.