4 x 12au7 Raytheon Tubes

Made in USA

Long Black Plates

D-Getter

Matching Codes 57-42 = 1957

Tested on calibrated Hickok 6000A

1800/1660
1800/1680
1810/1700
1670/1810

Mutual Conductance(100%) = 2200/2200

The auction is for 4 tubes