- Z1 EPT KMC's latest breakthrough in rust protection. EcoProteQ treatment doubles the rust resistance compared to the RB treatment. Benefits of the smoother coating are less noise, great performance, maximum rust resistance and great look. Higher Inner plates prevent chain drop. * 1/2" X 1/8" - 112 / 128 Links, pin length 8.6mm * For Internal gear hub / single speed * Extra long 128L version for e-Bike * EcoProTeQ Coating (EPT) Anti-Rust technology * Less maintenance * High reliability * No Drop