... 5.Process:forging 1.Product:Mini Excavator lower roller PC20-3 2.Warrenty:6 months3.Track toller ... effect:The function of the track roller is to convey the weight of an excavator ... a very good sealing to prevent dirt, sand, and water from damaging it.4.Main Product: Track roller,Carrier roller ... ,Bucket ear,Round ball,Yoke,Spring,Idler Yoke,Roller Guide,Bucket bushing,Bucket pin and so on ...