Rollers according to this standard are used for chains according to DIN 8167 part 1 and part 3 and chains according to DIN 8168 part 1 and part 3 and serve as support and guidance on roller rails.
DIN 8169:1999 history
2014DIN ISO 1977:2014 Conveyor chains, attachments and sprockets (ISO 1977:2006)
1999DIN 8169:1999 Rollers for conveyor chains of ISO-types M, MT, MC and MCT with solid and hollow pins