EF Johnson porcelain tube sockets

[k4kyv]

The number on the  socket indicates the size.  The smaller ones, that fit the 811 and 866A are type 210.  The larger size that fits the 810, 250TH, etc is the type 211.  I suspect it is no coincidence that the smaller size fits the type 210 tube and the larger size fits the type 211.

BTW, I would be interested if anyone has a brown glazed ceramic version of the EF Johnson 210 socket (the smaller one).