1930 ANTIQUE POCKET VOLT METER 
BAKELITE GAUGE GERMANY 
HAVE MANUFACTURER MARK "K".
"D.R.G.M.","DEUTCHE BUNDES - GEBRAUCHSTMUSTER"
ORIGINAL, INTERESTING SCIENCE AND ENGINEERING 
TOOL IN GOOD, ORIGINAL ANTIQUE CONDITION.
LAST TIME IT WAS ONE NICE OBJECT 
IN THE PRIVATE MUSEUM EXPOSITION.
APPROXIMATELY FROM YEAR 1930.
I CAN NOT GIVE ANY WARRANTY 
ABOUT TECHNICAL STATE.
DECORATIVE AND ITEM IN 
GOOD ANTIQUE CONDITION 
(ALL, LIKE YOU SEE IN PICTURES).
MEASURES:
HEIGHT - 3"
LENGTH - 2"
WIDTH - 1"
YOU STRAIGHTLY WILL BUY THE ITEM,
WHAT YOU SEE IN THOSE PICTURES.
I HAVE SOME OTHERS INTERESTING ANTIQUE, 
ART NOUVEAU, MILITARY, SCIENCE AND 
ENGINEERING EQUIPMENT.
PLEASE SEE MY PROPOSALS. 
WILL BE SEND WITH VERY STRONG, 
SAFE, BOX PACKAGING.
I WILL BE GLAD ANSWER ALL YOUR QUESTIONS.
HISTORY:
This is a German pocket (fob watch style) D.C. volt meter, sold to and used by radio users who wanted to know the condition of their H.T. and L.T. batteries for their early valve radios. The meter, housed in a Bakelite case has two scales, one being 0-240 volt and the other 0-6 volt with a negative mark on the case above the contact pin. 
D.R.G.M. There was already a law on design protection in Germany from 1876, but as a result of increasing industrialization and the increased movement of goods, especially in the wake of growing economic interest perception on a national level, it was decreed that a new utility model was created. A Reichsgesetz of 1 June 1891 created the legal requirements for Germany, so that the Imperial Patent Office introduced the "German Reichs-Gebrauchsmuster" on 1 October 1891. Zahlreiche Produkte wurden so zwischen 1891 und etwa 1945 mit der Kennzeichnung „DRGM“ versehen, oft unter Hinzufügung der Musternummer, die es heute erlaubt, die Entstehungszeit mancher materiell überlieferter historischer Geräte auf ein bestimmtes Jahrzehnt einzugrenzen. [1] Auch einige Jahre nach dem Zweiten Weltkrieg war diese Kennzeichnung in Westdeutschland gelegentlich noch üblich, die Abkürzung lautete dann entsprechend "DBGM" (Deutsches Bundes-Gebrauchsmuster). Many products being made between 1891 and about 1945 bears the marking "DRGM", often with the addition of the pattern number that allows today to narrow down the time of origin of some material of traditional historical units to a particular decade. Some years after the Second World War II, this marking was still customary in West Germany with the abbreviation then corresponding to "DBGM" (German Federal Utility Model). is a German pocket (fob watch style) D.C. volt meter, sold to and used by radio users who wanted to know the condition of their H.T. and L.T. batteries for their early valve radios. The meter, housed in a Bakelite case has two scales, one being 0-240 volt and the other 0-6 volt with a negative mark on the case above the contact pin. This has a manufacturer’s logo mark of a letter K in a circle of which research continues to trace the manufacturer and the D.R.G.M. stamping on the lead contact pins confirming its German heritage.