Quantity   Component name
2 × DS2406+ Maxim Integrated Digital Switch
3 × 3.5mm 3-position PC-mount Terminal Blocks DigiKey Part # ED2636-ND or similar
2 × 3.5mm 2-position PC-mount Terminal Blocks DigiKey Part# ED2635-ND or similar
2 × 2N3906 Transistor or equivalent
2 × 2 LEDs (optional)
2 × 100k 1/8-/1/4 watt resistor
2 × 10k 1/8-1/4 watt resistor
2 × 220ohm 1/8-/14 watt resistor (needed only if using LEDs)