1) core barrel of double tubeswivel type
双层取心筒
2) double-tube core barrel
双筒取心筒
3) triple-tube core barrel
三层取心筒
4) double-tube core barrel,swivel type
内筒不转式双筒取心筒
5) double-tube core barrel ,rigid type
内筒转动式双筒取心筒
6) double core barrel drill
双筒取心钻具