Dienstglass EMV KF 6x30 Busch

[PanzerVI]

Hello gents

Came across this Dienstglass recently, marked EMV (kalterfest) made by Busch in Rathenhow. I understand this marking is quite a rare one, maybe someone can confirm. Appears to have been setup for the Kriegsmarine ?
Also the leather box appears to be other than the typical german, resembles more swedish imo.

Thank you for the info you might have.

cheers

[reneblacky]

Wish I could help, but I do have a pair with similar markings. Mine are marked for cold weather though.