The Marelon Integrated System valves were specifically designed for production boat builders. They offer more configurations and options than any other brand/style valves made for the marine industry. We can thread match the flanged bases to fit NPSM (NPT Parallel) in 3/4" through 2" or BSP from 1" through 2" for use on bronze or stainless thru-hulls. Our complete system comes with a flush or mushroom head "buttress" threaded thru-hull for exceptional strength. When the complete system is used we supply an emergency thru-hull plug as a cap in the handle. This plug can be used if needed by plugging the thru-hull from the outside to allow full disassembly of the valve to clear a clog or replace the entire body all without having to haul the boat. All configurations meet or exceed ABYC standards, are U.L. Approved and ISO Certified.