How to connect the single open and double control switch?

1. Install two switches at both ends and connect them with wires.

2. Select wires; Generally, the power of lighting lamps is relatively small, and a line of 1.5mm is enough.

3. When wiring, it should be noted that L is the incoming and outgoing line, L 1, and L2 is the connection port of two switches.

Double control switch is to control the switch of the same light in two different places, such as living room and stairs, so that we don't have to go back to the bedroom in the dark after turning off the light (entrance door), which is very convenient.