Description3-terminal (2 circuit) turn knob light socket set in table lamps with a night light in the base. This light socket is not a 3-way socket, it is a 3-terminal socket which controls 2 different light bulbs, one in the base and one in the top. It goes through this sequence: bottom only on, top only on, both on, both off. The top socket does not use a 3-way bulb unless it is wired separately from the bottom and the bottom has its own switch. Threaded to fit 1/8 IPS pipe, this medium based, stamped cap socket features a brite gilt finish, black turn knob, and can withstand a maximum of 250 watts at 250 volts. Screw set not included.