A drop key and crescent key are required to operate their respective Fireman switch and are available separately. Features The Drop Key Fireman switch is fitted with a heavy duty DPDT (plunger) double pole micro switch while the Crescent Key Fireman switch is fitted with a heavy duty SPDT (lever) single pole micro switch. With the rise in popularity of Fire Brigade Keys (now commonly called FB keys or fire fighter’s keys), many councils and other emergency services use the keys to avoid having to call out the fire brigade for minor emergencies. Facilities managers and council employees who need to carry out inspections, or need regular access to areas like electrical cupboards, or car parks, commonly hold a full set of Fire Brigade keys on their person at all times. Key Types: