JOB’s E-Bulb is filled with 3M™ Novec™ Engineered Fluid. This non-toxic, non-conductive extinguishing liquid is released into the device when the defined temperature is reached and the Thermo- Bulb bursts. After being initiated, the E-Bulb extinguishes the fire, and interrupts the electric current. Transition-free, the liquid immediately converts into gas.