Ring-hook for a German infantry assault backpack (A-frame) or for various backpacks. Independent development, made in Russia. The material is aluminium. No manufacturer's stamps.
The hook is painted hammer gray, which is better to sand off or wash before use, because aluminum parts of this type were not covered with paint, as a rule. You can wash the paint with "acetone" or "646" solvent or brake fluid (for a car). Acetone dissolves the paint instantly, and if you use brake fluid, the product must be soaked for several hours in it. The advantage of brake fluid over solvent is the absence of a sharp smell (although it still has a smell).
Price for 1 pc. Usually you need 4 for an equpment item.
Aluminum hooks were produced until 1940, and later used for sewing equipment for some time. After 1940, only steel fittings were produced.
The hooks were used in the "universal carrying" system, when the carrying strap (on the soldier's side) had standard rings, and the backpack, bag, etc. (on the cargo side) had standard hooks.