Quality vintage soviet ceramic tube sockets PLK7-D31 (ПЛК7-Д31) for miniature 7-pin tubes. Sockets are equipped with removable steel retainer. It is suitable for tubes like 6J1P-EV (6Ж1П-EB), 6J1 (China), 6F32 (Tesla), 6J2P (6Ж2П), 6AK5, EF95 etc. After very easy removal of the retainer they may be used for all heptal tube types. New old stock.