The Primagon is a shiny beauty from former DDR Meyer-Optik. It's a 35mm wide angle (certainly for its time) and with a maximum aperture of f/4.5, it is also relatively slow by today's standards. This lens has a M42 mount (there apparently also is an Exakta version) and bears the "1Q" symbol, indicative for "good quality".
Aperture range: f/4.5-f/22
Minimum focussing distance: 0.4m
Aperture blades: 10
You can take a look at the Primagon's dedicated gallery.