Very nice postally used solo cover from Latvia franked with se-tenant from the Mare Balticum booklet, posted to Lithuania. Postmark: "Daugavpils 20 - 1 November 1993", correctly franked with 10 Latvian rubles for 1st weight class.

Birds: Mergus merganser, Tadorna tadorna.
Engravers: Lõhmus, Sjööblom.