Type S fuses are a replacement for standard Edison base plug fuses. Using screw-in, non-removable adapters, Type S fuses have unique thread patterns in the various size ranges to prevent insertion of the wrong (over-amperage) fuse.
Here's a
LINK to a typical Type S fuse.
Sorry to say their lame search engine doesn't get me to a link to the screw-in adapter.
Hope this info helps...