SWK12GUU:Made in Japan:NB Linear Systems Square Flange Type Nippon Bearing Linear Systems SWK12GUU 3/4" Bore linear motion ball bushings/bearing, Bearing is seals on both sides, bearing inner diameter(bore) is 3/4" 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.