Energy Efficiency recom-mends this product only when installed according to Government Good Practice Guide 302.The Horstmann C-Stat is an electronic programmable room thermostat that combines time and temperature control in a completely new, stylish design that features a clear, back lit user interface.C-Stat uses the latest TPI energy saving software for accurate temperature control and which can produce savings of as much as 10% annually* on central heating fuel costs.All models in the range feature 24 hour and 7 day programming with up to six temperature settings per day. The intuitive interface ensures they are easy to set up and use. Being battery powered, the C-Stat 11-B and 17-B are suitable for replacing most existing room thermostats.The mains powered C-Stat 11-M and 17-M will not need replacement batteries.*TACMA figures Features. Voltage free contacts. Temperature Settings 5°c to 30°c. Menu driven programming via large back-lit display, with prompts to aid the user. Automatic BST/GMT time adjustment. Tamperproof Security Code. Target temperature and actual room temperature indication. Temporary temperature override. Holiday programme. Optional optimum start facility. Battery reserve (11-M and 17-M)11-B & 17-B battery powered 11-M & 17-M mains poweredC-Stat programmable room thermostats Horstmann.Together, we're in control.