Original Finnish army wartime general purpose canvas weapon sling for rifles, submachine guns and light machineguns. This model is seen in late-war photos fairly regularly.
This is a green canvas sling with varying colored leather reinforcements, a rectangular shaped steel buckle and a steel or brass button.
Some of these have SA and T stamps, some don’t.
This sling is great for Finnish Mosin-Nagant based rifles, Suomi submachine guns and also LS-26 and DP-28 light machineguns. For LS-26 and DP-28 you need two of these which allows you to carry them like a backpack.