VHT AV-TT-TT2 Tube Tester 2 Includes two standard 8-pin octal-base adapters with dual banana plugs Adapters accept all popular octal-base output tube types: 6V6, 6L6, EL34, KT66, KT77, KT88, 6550, etc. Two high-quality 3" diameter metal and glass analog milliamp meters (100 mA max) Additional test-pin jacks for external digital multi-meter connection Durable vinyl-covered wood cabinet