Vktech&reg; 3 in 1 E27 Base Light Lamp Bulb Socket Splitter Adapter For Studio Photography (3 in 1) It is a 3 in 1 studio E27 lamp socket splitter adapter for studio daylight bulbs It allows 3 bulbs installed in one single socket at the same time Each socket on the adapter can support up to 250W. So it support up to 750W in total This product idea for more lights for photo or video, if you want to upgrade your single socket lights, convert a single bulb light to 3 bulbs light, this is the best choice. It is E27 base, same fit as regular household bulb socket