4 Pin EF Johnson NOS ceramic bayonet socket (123-209-200) with (2.8" wide base) for 3B28, C3J, 8020, 811A, 812A, 866A, 572B
0) nickel collar
1) aluminum collar
 NOS for 811A / 572B / 866A (1 in stock) "Pin It")
 NOS for 811A / 572B / 866A (1 in stock)&Category=sockets&ImageURL=http://tubeworldexpress.com/cdn/shop/products/123209200a.jpg?v=1571438877){kind=link}