Please review the photos for more detail. Test results for Gm: 2.95 / 3.1 and 3.0 / 3.1. For Gm, 1.7 is the 60% reject point. For reference we used a Triplett 3444A Tester.The item "6SN7GTA Raytheon Audio Receiver Guitar Pre-Amplifier Vacuum Tubes Tested Pair" is in sale since Thursday, April 8, 2021. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Parts & Accessories\Vintage Tubes & Tube Sockets". The seller is "chukv" and is located in Westwood, Massachusetts. This item can be shipped worldwide.