New old stock, original box, Russian made 6X4R (Russian number 6U4Pi-EB) tubes. 1976 date codes. These are used in certain Audio Note preamps and some other Russian and audio gear. Please note that these have a different pin-out to regular US and European 6X4/EZ90 tubes (the cathode connects to a different pin), and are not directly interchangeable with those types.
This item is shipped from Britain, in North America or Asia please allow 2 to 3 weeks for delivery.