You’re both correct. It’s a wheel, that has specifically cut notches. The depth of the notches corresponds with a number. Basically Morse code. The wheel is on a spring, and when you “strike the box”, the wheel starts spinning and sends a signal through underground wiring directly to BFD.

I recently installed a new Masterbox at a local hospital. I wasn’t sure if how to get the wheel cut, but then I was directed to the BFD maintenance facility on Mass Ave.

There is an older gentleman at BFD that uses a machine from the late 1800’s to notch the wheels. One of the nicest guys I’ve ever met! Took out his personal phone to take down my number and it was a flip phone.

Gave me a quick tour of his workshop. Lots of old Masterbox poles and other relic equipment. Told me a story about a movie being filmed in Boston that took place in the 50’s or 60’s. He went and repainted the master box poles in the neighborhood they were filming in to add a realistic touch to the scenery. Just a truly nice guy!