Product review (5 stars): Good combination of switch/fuse/socket in a relatively small module
I don't know why people are complaining about the absence of a fuse. You should be choosing your own fuse by evaluating the current/in-rush current, materials, wiring, etc of your device. Or, try to find the information in the manual of the appliance that you're powering. (Keep in mind that this module has a 10Amp maximum rating.) Unless they want to send a very large assortment, it makes no sense for the manufacturer to send fuses when they have no idea what kind of device you're powering.

It requires a gma 5mmx20mm fuse. I've bought them at Home Depot, Lowe's, and Radio Shack. I think you can find them at some automotive stores too.