3 Brass tubes, which i found at home. I was too lazy to purchase brass, so one of the tubes was used for top and bottom plates. Brass is old.. so scratches everywhere.
ok, back to button. It is an ordinary part of shower faucet
- not this, just to show the part
I found old one of course. The one which i use is from mixer shower and bath valve.
Yes, button have magnets. To place them I machined button leg (firing pin) on the drill to the biger magnet inner diameter

Yes, button is rather heavy, but working like a charm