DESIGN: The adapter allows you to change an E40 thread to an E27 lamp socket in just a few steps. Now you can easily insert your E27 lamps into E40 sockets! FUNCTION: To convert your light fixture to the desired socket, simply screw the E27 adapter into the E40 socket. Then you can insert the bulb as usual! MATERIAL: Only high-quality flame-retardant plastic was used to manufacture the lamp socket adapter to make the product as durable as possible! COMPATIBILITY: If you don't have a suitable bulb at home, our high-quality bulb adapter is suitable for LED, halogen, and energy-saving bulbs! MISCELLANEOUS: Only the set of 4 E40-E27 lamp adapters is included in the delivery!