The 84-5231.2B20 is an illuminated emergency stop switch designed for panel mounting in a Ø 22.3 mm cutout. It features a maintained, slow-make switching action with a 'twist to unlock' release mechanism and a red mushroom-head actuator. The switch is configured with one normally closed (NC) and one normally open (NO) contact made of gold-plated silver, and has a rated operational voltage of 250 VAC/DC. With an electrical lifetime of 50,000 cycles and a mechanical lifetime of 250,000 cycles, it offers high reliability. Its robust design is rated for IP65, IP66, and IP67 front protection, making it suitable for industrial machinery, control panels, and other safety-critical applications in demanding environments.