The lamps can be mounted in different ways. This is just one example of many.
The height without the bulb is 6cm, with 12.5cm.
Each lamp requires 1x E27 / E26 Edison screw bulb, is wired, functional and runs on both 110 / 230 volts.
Bulbs are not included.
It is possible to install this device in all countries (USA, Australia, Asia, Great Britain, Europe,...)