The Timeguard STBT4 Electronic Boost Timer is a simple, reliable push-button timer designed for controlling immersion heaters, extractor fans, and other 13A resistive loads in residential and commercial settings. Simply press the button to boost your heating or ventilation for up to 2 hours \u2014 no complex programming required.\nTimeguard STBT4 Electronic Boost Timer \u2013 Key Features & Specifications\n\nBuilt for ease of use, the STBT4 offers four selectable ON time periods at the press of a button, making it ideal for bathrooms, utility rooms, and plant rooms where timed boost control is needed. It fits neatly into standard 25mm flush or surface back boxes and operates on 230V AC.\n\n--Simple push-button control \u2014 no programming needed\n\n--4 selectable boost periods: 15 min, 30 min, 1 hour, or 2 hours\n\n--13A (3kW) resistive switch rating at 230V AC\n\n--Fits 25mm flush or surface back boxes\n\n--Compatible with 1.5\u20132.5mm\u00B2 flexible cable\n\n--Conforms to EM.