This Honeywell T4 wired 7-day programmable thermostat is a must-have for any home with a gas or combi-boiler. It features a white, square shape with a 2-wire configuration and AA battery size. The thermostat is compatible with universal smart home systems and has frost protection properties. With control style push buttons and temperature sensor technology, this thermostat is easy to use and programmable for 7 days. It is made of plastic and has a voltage of 230V. The model is T4 and it is perfect for any home looking to improve their heating and cooling system.