concrete pump cleaning ball it is for cleaning concrete pump pipe, various size available. namerubber sponge cleaning ballsize(2inch) soft ,hard ,medium softOD 60mm (3 inch) soft ,hard ,medium softOD95mm (4 inch) soft ,hard ,medium softOD124mm (5 inch) soft ,hard ,medium softOD150mm (6 inch) soft ,hard ,medium softOD175mmOther sizes and types upon requestMaterialnatural rubberapplacationcleaning ...