переводник, обеспечивающий получение ствола скважины заданного диаметра(a kind of a true-gage assembly that is put piggy-back on a standard bit which will extend the life and create a much less aggressive gage setting for rotary steerables or on motors (Ian Gillis, president of PDC bit manufacturer and subsidiary of Precision Drilling, United Diamond) Dorian Roman)
