This B329 is a British Made double triode with separate cathode connections. The envelope carries the second Type designation of ECC82, this is placed above the B329 as the generally known name for this design in the UK was the ECC82.
An amplification factor of 17 is quoted. The data-sheet makes the point that Type B329 is the commercial equivalent of CV491.
The dissipation of each anode is 2.5 Watts and so the anode is quire wide to provide the cooling area required.
The B329 is a general purpose design not normally used at Rf and so no intersection screen is provided.
The thin glass tube envelope is 20 mm in diameter and the length excluding the B9A base pins, is 49 mm.