According to the May Caravan Club magazine, Milenco have advised them that mirrors must be marked with the current 'E11' number and only Milenco produce these. According to White Arches Caravans this requirement does not come into force until 2010. The Caravan Club aren't responding to my query on the validity of their article, but it would be sensible to buy mirrors marked "E11". These ARE available from several manufacturers, despite what Milenco claim. Milenco mirrors are good but I'm not sure I like their ethics as far as advertising goes!