Duplex chain is manufactured to BS228 / ISO 606 / DIN8187 / DIN8188 standards with hardened pins which prevent wear and stretch and also make it easy to dismantle. Roller chains are designed for demanding industrial and agricultural drives. Consistent quality, high-quality product. Our duplex is supplied in one of the following premium brands: Dunlop, Challenge, Medway and are produced to a high quality standard. Please Note: In the unlikely event that we should not have Dunlop stock available then a quality brand will be supplied.