SMSF30GUUE NB Round Flange With Pilot End Type Anticorrosion Made in Japan:NB Linear Systems SMSF30GUUE NB Round Flange Type With Pilot End Type, The retainer material is resin, Bearing is anticorrosion, Bearing is seals on both,series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), Made in Japan.