The 35Z4G is a half wave rectifier and was designed for early post war television use. Normally this Type is found as the GT version as in 35Z4GT.
Type 35Z4G would feed a 40 µF reservoir capacitor through an effective series resistance of 100 Ohms. The octagonal outline to the Type designation looks very much like an RCA design.
The anode size and form match the Brimar GT enveloped version seen in 35Z4GT.
The anode side view.
The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 91 mm tall.
References: Data-sheet & 1040. Type 35Z4G was first introduced in 1939. See also1939 adverts.