The use of seals or seals came probably from China to Tibet, this changed also the shape and the version of it in a early stage.
Tibet developed after a time a own tradition of production, including new materials, shapes and manuals.
The seals offered here were individual and personal Tibetan seals and were even used in past. They are distinguished from the Chinese seals that you can buy nowadays. These "new" Chinese seals are mass-produced goods, they just show a common symbol [e.g. a lotus flower or another symbol] without any meaning or relation to the owner.
The upper smaller part of almost all seals offered here tapers downward. This part of the seals served as a handle. The narrow middle part below is pierced. A leather strap was pulled through the resulting hole to attach it to the owner's clothing. Thus, he had it constantly at hand and could use it in his everyday life to seal his documents.
The last seal [No. 18] is a new one. It is an example for the nowadays offered mass production seals probably made in China.