Valve Inlet Threads- 2 Female NPT inside diameter is approx. Valve Outlet Threads- 2" Female NPT inside diameter is approx. Side Port- 1/8" Female NPT (inside diameter measures about 3/8"). Total Length of Valve: 4".There is an arrow on the valve that shows air flow direction for installation. Double check that you have this valve installed in the right direction before operating. Improper installation can cause damage to compressor pumps. California Residents Warning: This product contains or may contain chemicals including lead known in the state of California to cause cancer, birth defects, or other reproductive harm. California law requires this warning be given to all customers in the state of California. California Health and Safety Code 25249.5 et seq. If for any reason there is an issue with your order we will contact you right away. Feedback At Compressor Source we strive for great customer service and to sell the best quality parts at the lowest prices possible.