This Baxi emblem strain comfort valve is designed for Baxi Combi, Duo-tec, Duo-tec ErP, Megaflo, Megaflo ErP, Platinum, Platinum ErP, System, System IE, Main Combi/Combi HE, Main Eco, Main Eco Elite, Main Eco Elite ErP, Main HE, Gold, Gold ErP, Heatmax, Performa, Promax, Promax ErP, Titanium and Titanium ErP boilers. A must-have protection feature, the strain comfort valve is ready to open incrementally, relieving strain building up internal a heating system.