SMS6GUU-P Stainless Steel Anticorrosion Miniature Slide Bush Made in Japan:NB Linear Systems Nippon Bearing Miniature Linear Systems 6mm Stainless Steel Anticorrosion Miniature Linear Slide Bush, It is seals on both sides, NB SMS5G 5mm Slide Bush Ball Miniature Linear Motion Bearings, The retainer material is resin, SMS6GUU-P bearing is a Precision accuracy grade Miniature linear bushings, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), made in Japan.