Made of high strength cast iron with a chrome-plated, pressure balanced spool. These valves are interchangeable with Gresen selector valves. 6 port double selector valve diverts two flows in either of two separate circuits. Enables you to run two cylinders with one value. 3000 PSI. U.S.A. Material Type Cast Iron, Max. PSI 3,000, Max. Flow GPM 40, Port Size in. 3/4.