JT Drive Chains 520HDS2 NN version Products of the highest quality, ie top technology using special steel alloys of the highest quality. Lower weight with maximum tensile strength. - Silver with attractive nickel-plated inner and outer flaps, thus less corrosion - 2-fold reinforced ultimate competitive chain open with clip lock - 4-way pressed chain pins for extra strong hold against lateral forces on the outer flap - Stable, riveted bearing collar for permanent strength, as well as for an extra strong hold against lateral forces on the inner flap