The CV4503 is a miniature pentode with flying leads for direct wiring into a circuit. The operating parameters give a frequency of 50 MHz.
The three part leads that pass through the base have copper on the inside and flying leads on the outside. The central part has a coefficient of expansion that matches the hard glass base.
The three wire grids within the anode. The glass envelope is only 10 mm in outside diameter.
The thin glass tube envelope is 10 mm in diameter, and excluding the base leads is 36 mm tall.
Reference: Data-sheet. Type CV4503 was first introduced in 1960. See also1960 adverts.