Offered is a pair of RCA type 81 Half-Wave Vacuum Rectifier tubes.   One appears and tests like new and the other is used.  Both test good on the EICO dynamic tester and they show no shorts or inter-element leakage.  These tubes have big black ribbed plates and a lower getter with good silver flashing on both tubes. The boxed tube appears new and unused-this one has hot-stamped graphics and it is an RCA/Cunningham Radiotron. The Hot Stamped tube has date code: Z2 and the other has date code: K4.  Used in power supplies of very early AC radios generally in pairs.  Grab these two for your own radios or collection. Mouse over the photo images to zoom in.  NO RESERVE!! Thanks for looking.