I came across these in the warehouse and looked them up: these are Soviet era pencil triode tubes type SN-891B, I found info on them on the internet. Interesting curiosity piece. In another life, I saw Russian missiles stuffed with things that looked just like this… used as high impedance interface devices. I am selling one piece at a time. If anyone has a data sheet (in english…) I would like to hear from them.Have fun! Please see my other items for more RF goodies! I COMBINE ITEMS FOR LOWER SHIPPING CHARGES, ASK BEFORE YOU PAY.