This Symmons NS-1 shower cartridge is a genuine Symmons replacement part for ShowerOff series valves from 1983 to date. This metering cartridge is intended for use in ShowerOff valves in commercial applications, such as correctional facilities, public showers, or applications where metered control of water usage is necessary. Like all Symmons products, this item is backed by a 10 year warranty for commercial use.