One sold by Jacob, but by other firms as well.

2.

It has triangular indentations behind the bone ends. There's a 835 stamp, right side up, to the right inner band. - Bob

Nice one BB! This is a very well known German WW2 ring. There are period ads, rings with 100% provenavce, period photos in wear,true dug examples.
Every ring collertor should strive to have at least one example..

Here's a period ad for the exact ring..