WIRELINE SERVICES: Open Hole Logging Open Hole Tool Strings Tucker has some of the shortest and most versatile tool combinations in the industry. Stack Micro Stack Quad Stack Micro Quint Stack Arm Quint Stack For any tool string the only restrictions on placement are that the Gamma Ray tool is at the top of the string and the Phased Induction SFL tool is at the bottom Nav Pack directional tool may be run in any string to measure hole deviation and azimuth.