Features. Aqua Pro models are made of nontoxic foodgrade materials have 12 inch pipe thread. Check Valve Lead Free Direct replacement for Marshall Brass and for Hydronamic Products. 12 Inch Male Pipe Thread x 12 Inch Male Pipe Thread. Direct replacement for Marshall Brass and for Hydronamic Products. Made of nontoxic foodgrade materials. Certified to IAPMO and NSF standardsSpecifications. Dimensions 4 H x 2 W x 1 L in . Weight 3 lbs