2 way switches are generally used when there are two switches controlling one light. A typical example of this is when a room has two entrances (like a through lounge) where there is a switch positioned at either entrance. Made from high quality ultra slim, premium grade material Complete with integral gasket. Compliant to all relevant British safety standards. Minimum mounting depth: 16mm. Dimensions: 87.5mm x 87.5mm. Supplied in retail blister with full fitting instructions. 15 year guarantee.