Silicone rubber dome switch casting mold

This is a reusable mold for casting silicone caulk into rubber button domes. The 4mm conductive carbon rubber discs can be obtained as a TV remote repair kit which can be very cheap and contain a few tens of these discs, but I've never seen anyone selling one-button domes for use with custom boards. A rubber dome switch has a more game controller-like feel than microswitches, as factory made game controllers frequently use these. To use the mold, rub a bit of liquid soap onto each half, put the