NB SW6 3/8 Ball Bushings Linear MotionSW6: Made in Japan: NB Linear Systems Nippon Bearing Linear Systems 3 8" Bore linear motion ball bushings bearings, inner diameter(bore)= 3 8" inch dimensions with steel retainer, bearing is high accuracy grade linear bushings, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), made in Japan. Item: SW6 Linear Motion Ball Bushings Type: NB Systems Ball Bushings Linear Motion Size: 3 8" x 5 8" x 7 8" inch Inner Diameter: 3 8" inch