Up for sale is a matched pair (2 pieces) of authentic vintage Sylvania JAN-6SL7WGT dual triode vacuum tubes, preserved in protective white boxes. Manufactured in the USA for military specifications (JAN CHS series), these ruggedized tubes feature smooth black plates, a distinctive brown base, a  square getter, and clear green markings. Highly sought after by audiophiles for their exceptional durability, ultra-low microphonics, and warm, dynamic presentation in preamplifiers and audio circuits.

As shown, both tubes have been precisely tested on an advanced Amplitrex AT1000 tube testing system operating in full fixed-bias mode. Plate current (Ip) and mutual conductance (Gm) measurements alongside percentage performance ratings relative to nominal factory specs are detailed in the table below.