This is a medium base (E26), also referred to as standard or Edison base, phenolic socket that includes a shade ring.
It has a standard on-off interior with screw terminals that is rated 250 watts and 250 volts.
The bottom cap is threaded to accept a 1/8 IP rod or nipple (1/8 IP measures 3/8" diameter), and also has a set screw for a more secure fit, making it a great option for a pendant fixture or a table or floor lamp.
This socket is UL and CSA listed.
It consists of 4 pieces: a bottom cap, a top cap, an interior, and a shade ring.