1. non-drive gravity roller 2. nylon gravity roller 3. weld pipe gravity ... gravity rolle 5. spring loaded GCS non-drive nylon gravity roller, stainless gravity roller, weld pipe gravity ... , packaging line, conveyor machine and logistic store etc,2. GCS gravity roller has PP (press bearing) or ... gravity roller could be made of nylon, weld pipe, stainless steel. For nylon gravity roller, the color could ...