RK Chain RK525XSO-RL Silver Pro RX-Ring Rivet 525 Pitch Master Link Chain Fabricated from an advanced nitrile butadiene composite and featuring 3 lubrication pools to prevent heat, abrasion, torsional flex, and loss of lubricant. All chains are treated using RK exclusive HIT (heat induction transfer) process. Most chains are available in standard non-gold or distinctive gold color.