road roller  Tag

From Wikipedia:

A road roller (sometimes called a roller-compactor, or just roller) is a compactor-type engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations. Similar rollers are used also at landfills or in agriculture.
Road rollers are frequently referred to as steamrollers, regardless of their method of propulsion.

One of Kagamine Rin and Len's character items.