The U70 from M-OV was introduced in 1939 and is a full wave rectifier for small equipment. Later rectifiers also had the same rating and so this valve has several equivalents.
The two anodes are stacked along the common cathode tube. The overall front to back dimension is only about 2.5 mm.
The L shaped anodes are identical and just mounted up or down. The additional anode area is for heat radiation and to provide secure fixings.
The classic envelope is 38 mm in diameter, and excluding the IO base pins is 88 mm tall.
Reference: 1043. Type U70 was first introduced in 1939. See also1939 adverts.