Zahlkarte and Paketkarte. Original unused sheets of postage labels (for packages larger than letters) with money orders on the top. Price is for one sheet. They are a little dusty with some discoloration from storage, but are new old stock. They may ship to you rolled up. The sheets are perforated into sections.
When you shipped something, the receipt on the far left was ripped off and was yours. The label in the center was for the outside of the packet and the label on the right was a duplicate for inside the packet. I frequently see labels like this on old crates. There were several variations of the label, but some features, like the red triangle, seem fairly common.
When you needed to send money, you would keep the receipt on the left, the post office would keep the center section and the far right piece was mailed to the recipient like a post card.
Very cool find. Great for your collection or really great to make some first rate pocket litter or to dress up some packages and crates for camp.