... .4HK1212BK12121218129.3HK1312BK13121319129.3HK1412BK14121420129.3HK1512BK15121521129.3HK1516BK151615211613.3HK1612BK16121622129.3HK1616BK161616221613.3HK1812BK18121824129.3HK1816BK181618241613.3 Needle roller bearing used for general engineer:1.open type drawn ... outer wall,an inner ring roller bearingMore introduction on the needle roller bearingRNA22...2RS double sealed, no inner ring roller bearing ...