Up for sale is a perfectly matched pair (2 pieces) of ultra-rare WWII era Sylvania VT25 / 10Y single power triode vacuum tubes, brand new in their original government contracting boxes. Made in the USA, these holy-grail military-grade tubes feature iconic black plates, top leaf getters, crisp glass etching, and classic brown bakelite bases. Relevelled by audio purists for their sublime, holographic midrange, sweet extension, and unmatched linearity in custom Single-Ended Triode (SET) power amplifiers and driver stages.

As shown, both tubes have been thoroughly tested on our laboratory-grade Amplitrex AT1000 tube tester. Plate current (Ip) and mutual conductance (uMhos) measurements alongside percentage performance ratings relative to nominal specs are detailed in the table below.