An antique glass insulator still doing its job. Seen near the intersection of E. Shields Ave. and N. Maple Ave. in Fresno CA. USA on 05-10-20.

I can't tell exactly what it is, but right off the bat it looks like a CD 162.

(Edit 05-23-20): I've been told that it is most likely a CD 164; this was confirmed by examining the wire groove width more closely. Thanks go to D.L. for pointing this out.