MOV valve, type MSP41, marked 10E/530 ZOKJ, metallizing finish, (RMW/Y533 - McVitie Weston number), by M-O Valve Co. Limited, 1936.
MOV valve, type MSP41, marked 10E/530 ZOKJ, metallizing finish, (RMW/Y533 - McVitie Weston number), by M-O Valve Co. Limited, 1936.