The SMT-2W5 from smart temp has been designed to provide a solution to when you don’t have enough wires on a project for a given task when running new wires is simply too time or cost prohibitive. Using a single pair of wires, the SMT-2W5 will provide you the same functions as R,C, G, Y1, Y2, W1 W2.
Every tradie should have one of these as Van Stock.