Drill collar according with API 7 :1,OD from 3-1/2" to 11"2,ID from 1-1/4" to 3"3,Length is 9150mm or 9450mm4,connection style and size: NC23,NC26,NC31,NC35,NC38,NC44,NC46,NC50,NC56,,6-5/8"REG,NC61,7-5/8"REG,NC70,8-5/8"REG