These plug in cutouts had a short fuse attached to their plug-in handle and protected the transformer. Such cutouts were known as "widow-makers". They earned that acclaim on account of the possibility of unknown faults or short circuit(s) that could have been either due to the load side of the transformer or something shorted within the transformer itself. Inserting a fused plug into one of these cutouts under such circumstances certainly caused quite a ominous, surprising loud boom, sometimes with injury, especially when you are up on the pole on hooks hanging yourself out to make the physical connection.

By 1930 primary fuse cutouts were redesigned into a porcelain enclosure. Usually brown in color, linemen have sometimes nicknamed them as "chocolate boxes". These have a bakelite "door" with a round handle with the fuse holder on the inside of it, making a somewhat safer means of reclosing.