This thermostat is CQC, TUV, UL , RoHS certificated Fixed or movable mounting flange Bakelite ... requirementType of grounding:Metel casing of thermostat connect with grounding metal partsMounting type :big, small/high ,low loose collar; circular ... difference:Min5°c, normally 15°cTolerance:Min5°c, standard15°cCertificate:TUV , CQC ,ULApplications: Boiler hot-water, Vacuum cleaner, Duplicator, Electric ...