The RL2T2 is a directly heated battery triode. The word Wehrmacht and the logo place this as a WWII German valve. The shape and integral handle show that this was designed to be replaceable in the field. The 1.9 Volt filament indicates that this was to be used with accumulator LT supplies.
The logo and figures 43 and 39.
The locating key and maker's name on the handle.
The thin glass tube in plastic envelope is 21 mm in diameter and, excluding the base pins, is 84 mm tall.
Reference: Datasheet. Type RL2T2 was first introduced in 1936.