BTC 5139, domes with slider keyboard. A good and beautiful vintage rubber dome keyboard (Rubber dome, but not membrane. This thing has an actual PCB!) : r/MechanicalKeyboards
Is the the "BTC 78xx" a mechanical keyboard ? : r/MechanicalKeyboards
BTC 5106 White Power Management Keyboard - Newegg.com
foone🏳️⚧️ on Twitter: "@mwichary The famed DOUBLE ARROW KEYS BTC ergonomic insanity keyboard. I used one of these for most of the early 2000s. https://t.co/0IV0xcmKv6" / Twitter