Boring Head Tool Holder Durable Adjustable Fine Tuning Precision Machining Kit. Name: fine tuning precision boring head. Precision: 0.01 mm. Features: fine tuning 0.01mm, large machining range of boring tools (20-1200mm). Internal water hole, direct cooling of the tip, longer service life of the insert. There may be some delays due to flight, holiday, weather, local post, local natural disaster impact. It must also be in the original packaging.