The EZ81 full wave rectifier almost replaces the octal GZ34 it has a maximum rectifier current of 150 mA against the GZ34 at 160 mA. Where they differ is that the GZ34 can operate with 550 Volts on the anodes whereas the EZ81 is limited to 350 Volts. This exhibit was made by Mazda.
In use the maximum reservoir capacitor would be limited to 50 µF and to prevent damage by excess current. An effective series resistance of 230 Ohms is used to achieve this.
Made in England on the glass and two stacked anodes within.
Unlike the lower rated EZ80 the EZ81 anodes have additional flanges to increase the anode surface area and thus allow it to radiate more heat.
The thin glass tube envelope is 21 mm in diameter and, excluding the B9A base pins, is 68 mm tall.
References: Data-sheet, 3002 & 1040. Type EZ81 was first introduced in 1954.