The PB Foam Gun offers excellent performance at a reasonable price point and is built to last. The main connector is constructed from solid brass, giving it excellent long-lasting performance and durability. The pistol grip, foaming tip, injector head lid and hoselock connector are all made of heavy duty polypropylene, while the bottle itself is made of chemically-resistant high-density polyethylene (HDPE). The multi-ratio injector head lid offers six settings to adjust the dilution rate from 300:1 to 10:1 (flow from hose:flow from reservoir) and built-in filters ensure any sediment in the water supply is removed before it reaches your car. An anti-siphon valve protects the water supply by preventing the snow foam solution from being drawn back into the hose (when the water supply is turned off, you may notice a small discharge of water from the base of the grip; this is normal and indicates that the anti-siphon valve is functioning properly).