This is the 4 round .17HMR & .22WMR magazine for the Weihrauch HW60 and HW66 series of rifles.
Their .17HMR and .22WMR rifles share the same magwell as the .223 and .222 versions so this is a .223 magazine with an alumnium insert and bullet feeding guide to take the smaller magnum rimfire rounds.
Weihrauch magazines are crafted from high quality blued steel to match the finish of the rifle.
Also fits late production Krico 301 Luxus rifles manufactured for Krico by Weihrauch, note the baseplate design.