Reasonably priced dust mask that won;t fog up my specs?

[thetyreman]

be weary of fake 3M filters on ebay, I bought some recently and am convinced they are fakes, there is something just not right about them

 

[ColeyS1]

be weary of fake 3M filters on ebay, I bought some recently and am convinced they are fakes, there is something just not right about them

Have you got any pics of them ? Someone may be able to shed some light, perhaps 3m themselves ?

Coley