Transformer: With the help of the lamp holder, you can easily convert an E40 socket bulb to an E27 socket. The assembly is very simple and highly compatible, it can be used with a variety of lamps! Simple to use: Just screw the adapter into a lamp with an E40 socket. Then, you just need to use a light fixture with an E27 type bulb. 4X PLUS: The package includes 4 adapters. Convert multiple E40 threaded bulbs to provide maximum brightness for your home! Provide maximum lighting for your home! Compatibility: The adapter is suitable for all E27 base bulbs, such as LED, halogen or CFL.