MettleAir CVU-6-KV Viton/Kynar Non-Return Universal Barbed Check Valve, Aquarium, 3/8" NPT (Pack of 10) Part #: CVU-6-KV Model: 3V210-08-AC220 Tubing ID 2: 3/8" Type: Hose x Hose Barb Check Valve Please measure prior to ordering, photo enlarged for easy viewing, scale may be distorted