BRIMAR, British Made KB/AD Pair CV4024 ECC81 12AT7WA Valves Tubes Black Box Plates, Halo Getters Fully Tested on AVO VCM 163 100% Book Spec = Ia 10 - Gm 5.5 1) Ia 9.7/10 - Gm 4.9/4.7 2) Ia 8.9/11.7 - Gm 4.8/5.7 New Old Stock, Supplied in Original Military Boxes |