What is the purpose of the Black Boxes NCAA Officials wear during games?

[observer]

As an observer, I am somewhat not real happy with the devices.
Or possibly "rules" should be made up to utilize the boxes.
I see too many (almost all) D1 officials reach for the magic button
on the belt devices to start the clock...Even the official that administers
the throw-in...Thus, one of his/her hands is used to hand the ball to
the thrower, the other hand is on the devise...No hands left to start
or chop the clock. Not every official on the floor needs to start
the clock on every position.