SIGMA CI rollers with single frictioned pinion sproket are mounted directly on crawl bushing. Roller weight load will increase friction between sprocket and bushing. This will create, in normal conditions, suffi cient coupling to pull the packages. Single frictioned pinion sproket SIGMA rollers are suitable for medium and heavy duty conveying, even in harsh environmental conditions. One piece casing, with welded tube and housed bearing. Integral bearing protection is given by triple labyrinth, anti-abrasive rubber lip ring, and additional screen guard. Type 6202 bearings are pre-lubricated and sealed for life.