I believe "manually-operated user-select equipment" is an attempt at a joke. Since 1964 when the first mouse was introduced by creator and inventor Douglas Engelbart, the device has been called a mouse simply because Engelbart thought the cord coming out of the small, wooden, three button device made it look like a mouse.

As for the mouses/mice/meese/moose debate. I have not seen "mouse devices" used but I have seen "computer mice" but by far, the most common plural I have seen, and in fact use, is "periphreals."

My 2¢ worth.