Maplin do various types, if you have one from this page http://www.maplin.co.uk/search.aspx?MenuNo=330&MenuName=5mm%2B12V%2BStanda rd%2BLEDs&worldid=3&FromMenu=y&doy=9m7http://www.maplin.co.uk/search.aspx?...andard+LEDs&wo rldid=3&FromMenu=y&doy=9m7 then your fine, the others require resistors. Its easier just to get one of these in my opinion, save yourself the hassle.