The Schmersal AZ 16-12ZI-B6R-M20 is a safety switch with a key-operated lock, an AZ 16I actuator, an IP67 rating, and a black plastic body. It is designed for safety-related switching operations and is typically used in combination with the corresponding safeguarding system. It is suitable for use in potentially explosive atmospheres such as in places where hazardous dust and gases are present. The switch has two positions: neutral or trip. When the key is inserted, the switch is activated in either the neutral or the trip position. When removed, the switch is deactivated with the last setting maintained. The AZ 16I actuator makes the switch easy to use with a precise, ergonomic grip, while the IP67 rating provides protection against dust and water, making it suitable for use in rugged, harsh environments.