Timeguard TRTD7N Economy7 Digital Time switch is a product from reputable Timeguard brand known for its excellent quality and reliability. brand ensures that you can trust their products to perform as promised and be easy to install and use with confidence. TRTD7N is a digital Economy 7 programmer designed for single, dual, or twin element immersion heaters. It features pre-programmed automatic boost, three on-demand options, a countdown boost display, and can accommodate up to 3 off-peak hot water or heating periods every 24 hours. This time switch also offers an easy view 12-hour AM/PM clock/timer display, simple push-button settings, select modes, and automatic summer/winter changeover. Dimensions: 111.5 x 170 x 60mm (H x W x D).