Sram PCXX1 Eagle 12s chain Outer plates nickel-plated and PVD black coated Inner plates chrome and PVD black coated Recommended for groupsets: XX1 Eagle™, X01 Eagle™ FlowLink technology reduces chain friction with the cassette, ensuring a longer chain life and quieter operation Hard Chrome technology strengthens the chain links with chrome, achieving very high chain durability The most durable and quietest chain PowerLock chain lock Chain length 126 links For 12-speed systems