The rectangular welding spots are characteristic for magazines produced by Erste Nordbohmische Metallwarenfabrik (ENM). JVD is the secret code assigned to ENM and this company used the inspection stamp E/WaA706.
Magazines of the 18th type were stamped with the P38 designation on the left side of the housing. The ENM code jvd and the ENM Waffenamt E/WaA706 were stamped on the spine. The position of these markings may vary.
This magazine was produced by ENM and issued with late war Spreewerk pistols.