I must agree with Ian C 31st May 2011 comment review, and will be returning these to Amazon.
These fuses have the wrong colour code and rating stamped on them.
I wanted to replace a 10 amp (red) fuse and could not decide on one from the twenty because of the variation in the fuse thickness. (This is the bit that blows when current flow exceeds the stated figure on a fuse).
I am concerned that other people could experience further blown fuses and just pop in another one, just because they are cheap.
Getting the fuse selection wrong because of the colour- coding and the stated rating could be very dangerous.