Empty octagonal pocket solid brass design 80s

Empty octagonal pocket in solid brass design of the 80s. Nice overall condition. Rare and discreet traces of common use in places (rare oxidation points in places and some scratches of use in the bottom. See photos of details and zoom). Very qualitative piece with a weight of 500 g. The length from edge to opposite edge is 20 cm. The inner diameter of the concave part is 13.5 cm.