Independent timing. 5-wire installation. Override facility. Holiday mode. Automatic BST/GMT time change. Boost function. EN 60730-2-7. Specifications:Switching/contact rating: 3(1)A. H x W x D: 88 x 135 x 32mm. Backplate fit: British Gas Standard. Suitable for underfloor heating. Suitable for Gravity-Fed & Fully Pumped Systems. 5 Wire Installation.