The 6U5G is an American Magic Eye tuning indicator and its construction follows the normal pattern. The electrode assembly is mounted centrally in the envelope and the display is viewed through the dome.
Printed on the base is the Brimar name and Made in England.
The display bowl with the amplifier triode below.
The wide glass tube envelope is 28 mm in diameter and, excluding the UX6 base pins, is 86 mm tall.
References: Datasheet, 1043 & 1040. Type 6U5G was first introduced in 1937.