SM150UU Linear Slide Bush, bearing is Seals on Both Sides, bearing is a Precision accuracy grade linear bushings, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), made in Japan. Number of Ball Circuits: 8. SM150UU Type Seals on Both Sides: Slide Bush Made in Japan:NB Linear Systems Nippon Bearing Linear Systems SM150UU Linear Slide Bush, bearing is Seals on Both Sides, bearing is a Precision accuracy grade linear bushings, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), made in Japan.