SMSFC16UU NB Center Mount Round Flange Slide Bush Made in Japan:NB Linear Systems Nippon Bearing Linear Systems SMSFC16UU NB Center Mount Round Flange Linear Anticorrosion Slide Bush, The retainer material is steel, Bearing is seals on both sides, Bearing is anticorrosion, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), Made in Japan.