For SIZE and PRODUCT INFORMATION ** scroll down page **
Size
Threaded: 4/36
Overall Length: 1-3/8"
Lamp Socket Turn Knob is an easy to grip brass knob. Extends approximately 1-3/8" away from lamp socket. Simply unscrew plastic turn knob and replace with brass turn knob. Fits most standard lamp sockets, however does not fit mogul or fat boy sockets.*