John Guest Speedfit Under Floor Heating Service Kit For JG/CONTROL4 MVKIT03Full internal service kit for the JG Control4 and JG Control 5 mixing valve JG Underfloor internal service kit for JGCONTROL 4 and JGCONTROL5. Includes replacement thermostat and spring for the UFH mixing valve, as well as pre lubricated replacement seals for the mixers brass temperature adjustment. Features and benefits Includes a replacement thermostatic element and spring. All pre lubricated mixing valve seals included. Suitable for underfloor