All of our Nickel Lamp Sockets listed below are UL listed. They will accommodate any standard household bulb (Medium E26 base). All are rated for use up to 660 watts except the dimmer sockets which are rated for up to 150 Watt. The dimmer sockets are also rated for 120 volts and will not work at 220 volts. The rest are rated up to 250 volts. The base of those sockets is threaded 1/8 IPS which will fit a standard lamp pipe.