Pancake design , made of strong and light space l material Tital-919 alloy to improve the strength and life; Wide application range. One power unit head can be used with Several working heads, add-on reducer inserts or interchangeable Cassettes, no need for special tools; oupler. Completely free of space restriction; Interchangeable working head covering all sizes, more safe; Ultra-light, ultra-thin and big torsion fit for various highly Difficult spaces. 1 strong abs case for 1 pc