Mains 220-240V AC 50Hz. Requires 3 wire connection, L. Ls, N (see Product information) 20 watts power consumption. Extraction rate 21 litres per second, 75 cubic metres per hour Sound output 41 dB[A] @ 2m. Can be wall or ceiling mounted No backdraught shutter. IP44 rated. BS EN60335 Dimensions: 167mm wide x 167mm tall x 40mm deep (beyond installed surface). 99mm diameter spigot, extends for 54mm. For connection to 100mm / 4 inch diameter ducting This model requires THREE electrical connections - permanent live, switched live and neutral. It will not function unless you have these three wires to connect!