12 volt fan measuring 92mm x 92mm complete with short cables,these can be used with a 12v battery,a 12v powersupply or directly from a solar panel,these will work with panels of 6v 250mah and above but if you want optimum performance they work best with 12volt panels with an output of at least 200ma,in other words,12 voltpanels of 4 watts and above,great for ventilation in greenhouses,conservatories etc,price includes vat and delivery.