Together with a LED- and a control circuit board an optical system of a collecting lens and a scattering lens is placed in a plastic housing. Signals with different lenses for signal positions left or right of the track are available. The signal lamp is protected against humidity, dust and damages by a massive pane of glass.
The different LEDs are supplied by an electronic circuit building a current source.  The inserting of the cable can be realized through a cable entry hole in the housing. A double wire connection is sufficient to connect the signal lamp to the interlocking or the control box. Optionally a protection tube can be supplied to avoid mechanical damages to the cable.
A door at the back of the housing enables the maintenance stuff to open the signal lamp. The door is equipped with a sealing and a snap lock. The existent thermal protection cover helps to complicate unauthorised opening.

Three fixing bolts are foreseen to mount the signal lamp to the signal screen and to align it with the track. A fixture can be used to place a telescope for positioning the signal lamp. The signal lamp can be equipped with a sun protection screen. A clamp band is used to fix the screen.

he availability of the signal lamp is calculated to a conditional probability of failure of 2% in 10 years under normal conditions. The maximum of the light intensity varies dependent on the colour of the signal lamp between ca. 1700 and ca. 4800 candela. Dependent on the intensities, required by the client, different values can be adjusted in the factory. The diameter of the light emitting area is 130 mm.

Independent of the different colours of the light all signal lamps fulfil the same safety requirements.
LED: In case of a shortcut or an interruption in the LED-unit, no signal (flash or static) is visible.
Control unit: In case of a shortcut or an interruption at the control-unit, no signal (flash or static) is visible. Is the control unit provided with over- or under-voltage, no light is visible.