SW32UU Seals on both sides NB Nippon Bearing Linear Systems Made in Japan SW32UU 2" Bore linear motion ball bushings/bearings, SW32UU is Seals on both sides, inner diameter(bore) is 2" inch dimensions with steel retainer, Bearing is a high accuracy grade linear bushings, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), made in Japan.