... either single or double sprockets , and are welded onto the roller tube.Double sprocket conveyor rollers are ideal for heavy duty material ... for light duty conveyorsystem applications.Length of roller : from 300mm to 1500mm is okDiameter of roller: 38, 50, 57, 60, 76, ... 89mmDiameter of shaft:12, 15, 20mmMaterial of roller: stainless steel or carbon steel, with zinc/plastic/rubber coated