Umbonium vestiarium, common name the button tops, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.

[1] The solid, rounded shells are up to 2 cm wide.

They are similar to Oxystele but are more flattened and show a glossy, highly variable and colourfully patterned exterior.

[1] They can be found on eulittoral sand.

In Vietnam, they are called "ốc ruốc" and commonly sold as a snack.