APM Bicycle Chains have Harder hollow pin ensures 360° riveting & light weight, 4-edges chamfers help quick shifting. Hollow plates results ultimate lightness. Inclined internal bridge for agile shift. Inclined outer bridge for agile shift. Deep inner chamfer helps rapid shifting. Ni-PTFE Teflon Coating, including inner plate, outer plated and roller parts, Superior Anti-Rust function was offered by APM Chain.