Designed with an oversized 50 mm valve, this is one of the largest valves available with the highest flow capacity. The body and all internal components are CNC-machined from 6082 aluminum alloy, anodized for a long lasting, corrosion-free appearance. The valve seal utilizes a Viton O-ring that is glued in place to prevent the possibility of sticking to the seat and pulling out. The blow-off valve comes with one quick connect pneufit fitting, with oversized 1/4 connection for quick and actuator response. If needed, barb fittings are available. The included "blue spring" is rated for 0.35 - 0.50 bar / 5.07 - 7.25 psi. Alternative, a "black spring" rated at 0.50 - 0.75 bar / 7.25 - 10.9 psi or a "white spring" rated at 0.00 - 0.35 bar / 0.00 - 5.07 psi can be installed (not included.) This V-Band clamp is set up for connection to a silicon hose with an inner hose diameter of 50 mm.