SMSF25UUE NB Round Flange With Pilot End Type Anticorrosion Made in Japan:NB Linear Systems SMSF25UUE NB Round Flange Type With Pilot End Type, The retainer material is steel, Bearing is anticorrosion, Bearing is seals on both sides, series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), Made in Japan.