Chicago Faucet Shoppe - 2500-EXT - 1 inch total extension kit for the Chicago 2500 series thermostatic valve. The 2500-ext kit will extend any 2500 series Chicago Faucet Valve rough 1 inch from original installation. This is the perfect kit if the faucet is roughed too far in the all or after a remodel job. 2500-EXT works on F M Mattson and Chicago Faucets manufactured valves.