Edison Screw Lampholders are widely used in Europe and are being fitted here. They have a 40mm dia. body and can be in a metal or plastic and a range of colours. When the ES Lampholders are used with a shade you need a large shade fitting. These Edison Screw Lampholders are also known as ES or E27 which is the larger of the screw types in domestic use. The E27 refers to a diameter of 27mm across the thread or cap.
"E27" refers to the type of base the lampholder accommodates. The "E" signifies an Edison screw mount, and "27" refers to the 27mm diameter of the base.
You can use any light bulb that has an E27 base, which could include LED, incandescent, or compact fluorescent bulbs.
In the UK, an E27 lampholder should comply with British and European safety standards such as BS EN 60238.