I have a CIY Tester68 which comes with a 2.4GHz receiver, and also features Bluetooth 5.0. The hot-swappable board (no switches and keycaps) cost under $15 and

I have a CIY Tester68 which comes with a 2.4GHz receiver, and also features Bluetooth 5.0. The hot-swappable board (no switches and keycaps) cost under $15 and powered by 2 x AAA.