You are looking at a pristine and very rare NIB NOS Beckman 931 electrometer tube. This is a genuine ultra-high quality USA manufactured instrumentation tube. Beckman only used the absolute best tubes available or purpose built for their needs. This collectable tube has been described thus - This is an original 931 Beckman Electrometer Tetrode replacement tube - originally a Sylvania 1229 derivative based on the Type 32 vacuum tube and selected for lowest grid current with additional shielding added. This is a rare, hard to find, classic four pin tube. It is useful in many older instruments, special circuits, VTVMs, old time receivers, transmitters and transceivers. Useful for antique radio, instrument restoration projects or to set up a private vacuum tube museum.

This tube is guaranteed fully functional and not DOA.

Please read the details below on shipping

.All tubes are guaranteed not DOA. Shipping is by Australia Post and charged according to their rates for different zones around the globe. If you wish to check out the zoning and charges please visit auspost.com.au. The minimum shipping weight is 500gm, I pack tubes very well and I have only ever had one problem with damaged tubes in over 10,000 sales. There is a very small handling charge to cover packaging and handling. I do not profit from shipping and I wish I could charge less. I am a registered business and pay all the appropriate Australian taxes including 10% GST. 

Domestic shipping for this item is $12. Overseas shipping costs depend on which Australia Post destination zone your country is in.The charge stated in the invoice will be for Europe where shipping with tracking is $28 for France. Some destinations are more expensive than Europe - Russia is $34 and Israel is $36. Shipping to the USA with tracking is cheaper at $24 because it is in a different zone from Europe. If you live in a cheaper zone than Europe I will refund the difference ASAP on payment. Please Email me to know the specific shipping cost to your country.

Please Email me if you have any questions about this item and I will reply as soon as possible.