There's a small clamp behind the hole in the front plate. The device below is actually just a double-pole switch with cord ("flex") outlet and no fuse, but the arrangement is similar:
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[Linked Image from members.aol.com]

Many of the current-production units have the cord emerging downward from the bottom of the plate and a simple cord grip similar to that you can see in the plug.



[This message has been edited by pauluk (edited 07-14-2002).]