JT Drive Chains 525X1R Products of the highest quality, ie top technology using special steel alloys of the highest quality. Lower weight with maximum tensile strength. 525X1R series - Reinforced X ring chain open with rivet lock - X-ring sealed chains provide significantly better protection against premature wear - 4-way pressed chain pins for extra strong hold against lateral forces on the outer flap - Sturdy bearing collar for strength with permanent impact