Whale in-Line Check Valve 3/4''In-Line Check Valves are perfect for preventing back-flow through hoses and for maintaining prime in a suction or discharge line. Available in two models, the larger one fits both 1'' and 1-1/2'' hose, and the smaller version fits 3/4'' hose. Suitable for use with manual or electric pumps.Features of Whale in-Line Che..