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,\.) up to 250v (europe/uk standard).the wiring of this item may be original and might need replacement, if not specified otherwise.