Key switch 

Panel cut-out (mm): 15.1 x 15.1

Elect Rating: 250Vac, 100mA

Dimensions (mm): 18 x 16 body style A

                              18 x 18 body style E

Actuator: key (common or differs)

Key: Nickel silver

Body: Glass-fibre reinforced nylon

Springs: Stainless steel

Contact: Moving - gold-plated phosphor bronze.  Fixed - gold-plated brass

Terminals: 1.01mm dia x 3.3mm gold-plated brass

Mounting: Retaining clip

Switching Function: Double pole changeover or 3 circuit selector