SMST6GWUU NB Two Side Cut Double Wide Bearing Flange Anticorrosion Slide Bush Made in Japan:NB Linear Systems Nippon Bearing Linear Systems SMST6GWUU NB Two Side Cut Double Wide Flange Anticorrosion Slide Bush, The retainer material is resin, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), Made in Japan.