... needle bearingMain structure frame:NK- needle bearing without inner ring, light seriesNKI- needle bearing, light seriesNKS- needle ... bearing without inner ring, heavy seriesNKIS- needle bearing, heavy seriesRNA48, RNA49- needle bearing without inner ring, size series 48 49NA48 ... , NA49- needle bearing, size series 48 49NA69- needle bearing, size series 69NSK THK ...