Metrawatt of Germany made the Horvex line of meters, of which there are three major versions. The original came out just before the war. This Horvex 2 is from the mid-50s, and the Horvex 3 showed up around 1960.

A simple little meter. Aim the little arrow on the calculator dial at the needle and read the pairs. There's another arrow if the accessory photocell is plugged in. That was a Horvex special feature, and common to all their meters.

Metrawatt fell into Eastern Germany after the war, and their US availability (along with Pentacon and most other DDR products) was pretty weak, so Argus branded them as their L3 model. Exact same meter except for the branding on the dial and the color of the case (the Argus is black).