The Worcester 77161920020 Bosch CDI Mechanical Timer is a compact and corrosion-resistant timer designed for indoor use. With an analog display and adjustable thermostat, this timer is ideal for controlling your heating system, whether it is powered by corded electric, gas/petrol, or NG (Natural Gas). The grey colour and sleek design make it a stylish addition to any home, while the reliable Worcester brand ensures high-quality performance. Perfect for maintaining a comfortable and efficient heating system in your household.