This is a bypass check valve. This check valve is not used to prevent backflow like most check valves, it is used to allow water to go around a filter or other equipment by going thru another plumbing path that meets the filter plumbing path downstream. Valve type: spring, spring type, strength: 5 lbs. Opens at 5 lbs pressure and is fully open at 17 lbs of pressure. Material: white schedule 40 pvc piping connections: 2" slip (actual inside diameter is 2-3/8" for 2" slip) Depth of plumbing connection: 1-3/8" (this is how far the pipe will extend into the 2" slip) Total length: 5" maximum outside diameter: 2-3/4"