This electronic On/Off wall-mounted humidity sensor from Vent-Axia is designed to automatically trigger ventilation when it detects a rapid increase in humidity and temperature, helping to quickly extract moisture-laden air from bathrooms and kitchens. The unit can be connected to a controller via the ‘Auto’ mode terminals. A night-time setback function prevents unnecessary activation due to gradual humidity increases caused by falling temperatures. The sensor includes a pullcord override, an indicator light, and a changeover relay switch. It operates within a humidity range of 30% to 90% RH and an ambient temperature range of 5°C to 40°C. Compatible with standard single gang surface-mounting boxes and runs on 220 – 240V AC.