Gm Tested NOS NIB QUAD GE 12AT7 Audio Amplifier Tubes
Here's a NOS quad of GE 12AT7 tubes On my B&K 747 gm tester where the reading is shown in percent of NEW tube value, these test as follows:118-125, 125-115, 110-125, and 106-120. It may or may not work at all when you get it!