SW16GUU Seals on both sides NB Nippon Bearing Linear Systems Made in Japan SW16GUU 1" Bore linear motion ball bushings/bearings, SW16GUU is Seals on both sides, inner diameter(bore) is 1" inch dimensions with resin retainer, Bearing is a high accuracy grade linear bushings, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), made in Japan.