M2SSK2-104 is a two-position key-operated selector switch from ABB's Modular Range pilot devices series. This maintained selector switch features key removal capability only in position B, providing secure operation control with key release code 74. The device is designed for 22mm panel cutout mounting and weighs approximately 1.6 oz. It is part of ABB's modular pilot device system, allowing combination with various contact blocks and holders for flexible configuration. Common applications include industrial control panels where secure, key-controlled switching is required to prevent unauthorized operation.