Fuse values


How can I determina fulse value in amps and type by looking at the fuse itself. The 5/20mm ones are hard to read.
ehoehn
Tvad, It has been so long since I have had to replace a fuse I forgot some of the things you mentioned. Thanks for the refresher course.
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I had to call/e-mail the manufacterer to find out. I couldn't read it either.