W42 is a panel sealing washer designed for use with Bulgin rocker switches. It is specifically intended for double contact switch body types, providing improved panel sealing capabilities. The washer reduces panel thickness by 1.00mm when installed. This accessory is compatible with various Bulgin rocker switch series including the 6050, 1500, and 1550 series, and is commonly used in applications requiring splash resistance or enhanced environmental protection at the panel interface.