Miniatur stupa or tchörten [»Tib. mchod rten«] tsa tsas, molded in the round and between 2 - 4 " | 5 - 10 cm in diameter. They also exist in larger dimensions in form of a pyramid. These are mostly of Mongolian origin. They are used in large numbers as a filling in large stupas. Consecration materials [mainly written mantras] are placed in a small opening at the bottom before the final sealing.
The cosmological symbolism associated with the World Mountain Sumeru and its different directions makes these votive offering small models of the universe. »Mount Meru« is in reality the Kailash mountain in West Tibet