Looking around for gu10 led replacements. Obviously I know that ebay can hardly be described as a recognised distributor but they do have many sellers of and a wide variety of led lights. Apart from the normal worries about buying from such an 'outlet', I am concerned that the lumens figures quoted could well be measured at different distances from the bulb. Would I be correct in assuming that if the bulbs have a certificate of conformity then this would confirm that the lumens measurement has been taken in a prescribed way and therefore ce certified bulbs can be compared on an equal basis?