The units conformed to the 1959-design for alternating current ( AC ) electrical multiple units , and were externally very similar to the Class 305 , Class 308 and the 1,200 V direct current ( DC ) Class 504 units .
The units conformed to the 1959-design for alternating current ( AC ) electrical multiple units , and were externally very similar to the Class 305 , Class 308 and the 1,200 V direct current ( DC ) class Class 504 units .