Metal housing with integrated heating element for the CD 400 and VD 400 when the detectors are mounted in cold and damp areas. The housing is supplied with anchor bolts, which ensure a wide detection area and an 150-ohm resistor that functions as internal heating.
The current consumption of the resitor is 80mA / 1W at 12V AC / DC and 160mA / 4W at 24V AC / DC, in both cases the effect is enough to prevent from a moisture inside the housing.