Envirovent SIL100T SILENT Extractor Fan 4" 100MM for Bathroom or Toilet with Run-on Timer\r\nFitted with motors mounted on silent elastic blocks, this fan delivers incredibly quiet running and exceptional performance with stylish features.\r\nThis model has a built-in run-on timer which means the fan comes on when you turn on the room light and then continues to run for a pre-set time after the light is switched off. This can be set to 5, 20, or 30 minutes. We also stock the nontimer model - see the separate listing in our shop.