The 6G5 (frequently grouped or interchangeable with the 6U5) is a classic "Magic Eye" tuning indicator vacuum tube featuring an octal base. It combines a high-vacuum triode amplifier with a fluorescent target screen to provide a visual tuning display for vintage radio receivers. Unlike the sharper-cutoff 6E5, the 6G5/6U5 features a dual-sensitivity shadow angle designed to prevent premature overlapping of the fluorescent sectors on strong signals. It operates on a 6.3V heater and fits standard 8-pin octal sockets. Available NOS and tested used.