Sirrus SK1500-3 piston and wax thermostat capsule with o-ring seal. Plastic Slider Diameter: 34.8mm (35mm)Included - Plastic piston - Wax thermostat - Black rubber o-ring sealThis piston and thermostat is used in a large number of sirrus thermostatic cartridges which are used in the following shower models:Sirrus St. James Thermostatic Shower Valve Shower Mixer ValveSirrus Vernon Tutbury Mixing Valve Shower Mixer ValveSirrus Turquoise Thermostatic Shower Mixer ValveSirrus Tern Thermostatic Shower Mixer ValveSirrus Ts 1850 Antique Shower Mixer ValveSirrus Bramham Shower Mixer ValveSirrus Opal Thermostatic Shower Mixer ValveSirrus Ts 1503 Thermostatic Shower Valve Shower Mixer ValveSirrus Santura Plc Antique Shower Mixer ValveSirrus Rothwell R996 & R997 Shower Mixer ValvSirrus Opac TS1503 Shower Mixer ValveSirrus Duette / Promix Thermostatic Bath Shower Mixer Shower Mixer ValveSirrus Mayfair Antique Thermostatic Shower Mixer ValveSirrus 1850 / 1850 Dual Shower Valve (including Sirrus Stratus 1850) Shower Mixer ValveSirrus 1500 - Thermostatic Shower Shower Mixer ValveSirrus Tre Mercati Thermostatic Shower Mixer ValveSirrus 1850 Dual Control - Thermostatic Shower Shower Mixer ValveSirrus Mayfair Dual Control Shower Mixer ValveSirrus Redring Dual Thermostatic Shower Mixer ValveSirrus Antica Shower Mixer Valve Sirrus Aquatania Shower Mixer ValveSirrus Britannia Shower Mixer ValveSirrus 1500 Antique - Thermostatic Shower Shower Mixer ValveSirrus Ts 1600 Thermostatic Shower Valve Shower Mixer ValveSirrus Ts1700 Shower Valve Shower Mixer ValveSirrus Diamond Shower Mixer ValveSirrus Heritage Dual Control Shower Mixer ValveSirrus Cifial Shower Mixer ValveSirrus Elson Thermostatic Valve Shower Mixer ValveSirrus Mayfair Antique Dual Control Shower Mixer ValveSirrus Bc Sanitan / Aquatania Shower Mixer ValveSirrus Ts1400 Thermostatic Shower Valve Shower Mixer ValveSirrus Pro Mix Bath/shower Mixer Shower Mixer ValveSirrus Rothwell R995 Antique Shower Mixer ValveSirrus Tre Mercati Antique Shower Mixer ValveSirrus Faucet Thermostatic Shower Valve Shower Mixer ValveSirrus Hero 6951-2 Single Shower Mixer ValveSirrus Ts 2000 Shower Mixer ValveFrequently Asked Questions: Sirrus SK1500-3 Question: My Sirrus shower goes cold after 5 minutes of use, even though a lot of hot water reaches the valve. Any reason for this? Answer: It sounds like the SK1500-3 piston isn't retracting properly or the element is faulty, so you could try replacing them to see if it fixes the problem. Question: What way does the thermostat go into the piston? Answer: Place the Sirrus SK1500-3 thermostat element into the piston with the gold metal body going into the pointed teeth part of the piston. Question: Is there a metal alternative to the plastic piston? I have replaced this once before but it keeps breaking. Answer: Unfortunately, the manufacturer only makes the SK1500-3 in plastic and as of yet, there is no metal version of this piston. Question: The product doesn't come with a spring. Do I need a new spring to fix my cartridge? Answer: Unless you have damaged the spring when you took the cartridge out of the shower valve then you can re-use your existing spring. We haven't had any person who had a faulty spring that was because of a manufacturing issue. Question: Why is the shower stuck on one temperature? Answer: A shower failing to regulate temperature is a symptom that the wax thermo-element has gone defective. You can test the element by dunking it in hot and cold water then see if the piston pushes up on its own and can be pushed down without resistance. If your shower's thermo-element is broken, the Sirrus SK1500-3 is a perfect replacement for showers mentioned above. Sirrus SK1500-3 Temperature Adjustment Thermostatic shower mixers automatically mix hot and cold water offering the right temperature in demand at the convenience of a shower user; made possible by the wax thermostat capsule, namely the Sirrus SK1500-3, the valve carries. These steps are for resetting the temperature on a Sirrus 1500 valve; it uses the SK1500-3 Thermostat and Piston. Check the water temperature with a handheld thermometer as you do the calibration. 1. Strip the valve of its handle. Then flick the front cap out with a flat tool. 2. Use an Allen key to undo th