I don't know what happened, I ordered them due to a blown fuse and they weren't nearly the same. I guess they make different sized fuses with the same numbers printed on them, but that's a problem when trying to find replacements.
I have 3 x 300w studio lights (used for short films) that stopped working the other day. My dad told me I probably just need new fuses. I found them and ordered them straight away. They sell at a great price and they work great. My lights shine brighter than ever.