Loose Ceramic Balls 5/16"=7.938MM ZrO2 (zirconium Oxide), this is a popular size that could be used in any application that uses this size 5/16",Ball is made of Ceramic ZrO2 . There are many sizes of steel balls. ProductSiteLaunchDate : 2024-11-25T06:10:24.297Z Size : One Size SupplierDeclaredDgHzRegulation : not_applicable SupplierDeclaredHasProductIdentifierExemption : 1 UnitCount : 1 UnspscCode : 31170000