Replacement switch for "Captive Key" Interlock System.
Commonly used on Cromartie and many other brands to comply with the Health & Safety Act 1974 still regarded as "best practice". Has a switching capacity of up to 60 Amps per pole and can be used for 3 circuits single phase or to switch the 3 lives on three phase.
Can also be used on "Double Pole" arrangement by using 2 of the 3 switched connections.