The thin glass tube envelope is 21 mm in diameter and, excluding the B8A base pins, is 53 mm tall.
EF41 was first introduced in 1947.
Not Licensed for sale in Gt.Britain
This Brand new valve- with original box & wrapper- never used before is " New old stock"
Details-
Qty-1
Box packing size- 10.5 cm x 3.0 cm.
Condition - New old stock.It's package Cover/ box has ageing issue.
Neither I have any knowledge or information to test it or any Valid source to assure its working.