ROTO LOC is an under reamer system for casing advancement, developed by Center Rock Inc. With wings that lock in place and are easily retractable, ROTO LOC is able to drill straight, full-diameter holes through any formation, including pinnacle limestone and karst. Straight holes into the formations eliminate bent or broken casing. Positive locking wings can be used to hold or pull casing back. In addition its rotary lockout feature ensures a full-size hole for greatly reducing casing friction. ROTO LOC saves drillers money because there are no expensive starter casing J-teeth or ring bits needed.