Assertion: medicine ball | /r/HasProperty | leather
Facets:
value: usually
type: DEGREE
Source sentences:
text: However medicine balls are rarely designed to be thrown onto a surface and are made out of less durable materials than slam balls and wall balls – usually leather, rubber or plastic.
text: Medicine balls are typically leather, gel, dense rubber, or nylon filled with sand, another filler, or even air.
text: The first medicine balls were leather.