If you, like me, like to sometimes undertake crazy electrical projects, these fused plugs will keep you a little safer in case if you make mistakes and cause short circuits, otor overloads, etc. You can insert any regular sized Buss fuse from Ace Hardware into this handy plug to protect you from short circuits, etc. Replacing a fuse is very easy. Just pull the rubber cover.
For sale is a lot of three such plugs. They are all new. Hubbell HBL5299.