One to three lamp adaptor and BC to ES converter.

This is an adaptor to allow three lamps to be put into a single lampholder. It's aimed at the photographic industry where they want a lot of light. It is intended for LED or fluorescent lamps and not for tungsten lamps due to the heat issues of a large cluster of tungsten lamps. Quit a nice thing, but with a few hazards typical of generic Chinese stuff. The fact it converts from a bayonet cap holder to Edison screw holders means that the outer thread of the lamp may be live. (It's supposed to be only the pin at the back that is live/hot.) The thread also sticks out far enough to touch. The connections to the lampholders are with uninsulated metal strip tucked under loose wire, so in the right circumstances it might be possible to get a shock from the back of the assembly too.
But other than that it's quite neat. It would look nice with LED candle lamps in it to make a simpler light fitting into a more glitzy chandelier type light.