Double Pitch Roller Chain Din 8181 (Iso 1275) Consists Of The Round (Pin, Bush-Bush, Rol) Used For Simplex Roller Chain Din 8187 (Iso 606) And Dual Pitched Plates. Roller Chain Dual Field Also Be Cast As Marathon Chain Maintenance Free, In Design Stainless Steel, With Bending Attachment, Attachment Straight And Pin Extended.