* Boiler spare parts must be fitted by a certified Gas Safe engineer * Orders received before 4pm are usually dispatched for next business day delivery. The Saunier Duval system pressure sensor is compatible with boilers in the C-CI, SI, Ultracom2, Xtrafast, Thema, Thema classic, Thema plus, British Gas, SXI, Isofast, Eden, CXI, Xtramax, Enviroplus, Energy, Isotwin, Ultimate, and Isomax ranges. It is supplied with a clip and an O-ring for fitting.