Triton 83307500 thermostatic cartridge. The 83307500 cartridge is a plastic and metal hybrid and is a screw fit installation.The thermostatic cartridge is used in the following Triton shower bars: - Triton Tay Thermostatic Bar Bath Mixer - Triton Tyne Bar Mixer - Triton Tyne Bath Mixer - Triton Tyne Thermostatic Bar Mixer Shower Spares - Triton Tyne Thermostatic Bath Shower Mixer - Triton Unichrome Aire Shower Bar - Triton Nene Shower Bar - Triton Exe Shower Bar - Triton Trent Shower Bar - Triton Wye Shower BarIf you are having problems regulating the temperature of the water in your shower then it's quite likely that the problem is the thermostatic cartridge (as long as the shower is receiving a balanced feed of hot and cold water). Replacing the cartridge should make your shower operate like new again as it's the heart of the shower valve.