Aquascape Check Valve Assembly PRO and Tsurumi Pumps | 29501 Connects pump to pond plumbing Helps prevent water from flowing back through the pump Specially-designed collar allows for easy disconnect For use with Signature Series 400/1000 and Pondless Vault filters; Tsurumi 3PL, 5PL, 9PL,and 8PN pumps; AquascapePRO 3000, 4500, and 7500 pumps Durable construction ensures years of trouble-free use