BKF 19-19-2 BKF 19-19-2.5 BKF 19-19-2/14.5/NPT BKF 19-19-2/M18 BKF 19-19-2/M20 BKF 19-19-3 BKF 19-19-3.5 BKF 19-19-3/14.5/NPT/S717 BKF 19-19-3/18.375/NPT BKF 19-19-3/M18