many types of step-chains for escalator ,horizontal moving sidewalk escalator chains .ST131,T131,JJT131,ST133,JJT133.etc. we are one professional chain factory ,producing ... chain .Zinc-plated,Nickel-plated,Docromet-plated etc.Comply with the standard of ANSI,ISO,DIN,BSetc.Quality can be guaranteed! escalator step-chain ...