What is this threaded lamp(?) piece called?
Closest I've found is &quot;THREADED CANDELABRA SOCKET CUP&quot;

I'm finding a couple of similar-looking items called &quot;lamp holder with threaded sleeve&quot;, for example:
Lamp holder E27 with threaded sleeve:

E27 BLACK THREADED SKIRT PENDANT STYLE LAMP HOLDER WITH 1/8IPS THREADED CAP:

E27 BLACK PHENOLIC FULLY THREADED SKIRT LAMP HOLDER WITH 1/8IPS THREADED CAP: