Air tank valves are constructed of high-quality brass for strength, corrosion resistance, high temperature ductility and low magnetic permeability for long-lasting performance; air gauges are constructed of yet strong stainless steel to provide years of accurate readings Our air compressor safety valve thread diameter is approximately 1/4 inch, which fits most air compressors, making it a widely applicable and practical accessory for air compressor models, suitable for discharging air, water and oil from air compressors machine, high-quality materials long-term performance Pneumatic relief valve is suitable for high temperature applications up to 250 degrees Fahrenheit, please pay attention to safety when using, safe relief working pressure is 200PSI, flow rate is 49 SCFM, temperature range is 32 -176 degrees Fahrenheit Practical function: The 200 psi pressure relief valve can reduce the excess pressure or vacuum in the system; when the pressure in the air compressor box exceeds the preset value, the valve opens to let the liquid or gas escape to reduce the air pressure Color: Gold Material: brass Package Contents: 2 x Air compressor relief pressure safety valves 2 x Air gauges Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.