SMF10WUUE NB Round Flange Double Wide Type Miniature Slide Bush Made in Japan:NB Linear Systems Nippon Bearing Miniature Linear Systems SMF10WUUE NB Round Flange Double Wide Miniature Linear Slide Bush, The retainer material is steel, It is seals on both sides, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), Made in Japan.