For crude and fine breaking rubber black and waste collection. Feature: 1.Being made of cold hard alloy castiron, the roll wears well.The rolls have 3 types:Double-channeled roll, single-channeled roll and double-smooth roll 2.The safety shut-down in manual operation is set, with the function of automatic or crawl back swig the roll 3.Convenient range adjustment is set in manually operation.The whole machine adopts hannel bottom head for convenient carrying and maintenance