Designed, assembled and quality checked in the UK, the LUMii contactor timers are the most robust and professional on the market. All earth requirements are incorporated into the lamp holder itself. Huge complete hydroponic grow room 3m2 tent fan filter 4 x 600 watt light kit the carbon filter can some times have carbon dust come through to the white outer casing making it blackish or grey this is not a issue and fine to use as long as the carbon filter is not dented.