Special shaped saw blade drill. The middle part is a saw blade, so you can slide it sideways after drilling holes. Can be used conveniently by mounting it to a drill machine or electric drill. A set of 6 sizes from 0.1 to 0.3 inches (3 to 8 mm). After opening, it can be stored together in a storage bag. -Product Specifications: Material: HSS Size (Drill Diameter): 0.12 inches (3 mm) / 0.24 inches (4 mm) / 0.24 inches (5 mm) / 0.25 inches (6.5 mm) / 0.3 inches (8 mm) (Drill Length): 2.4 inches (60 mm) - 3.5 inches (90 mm).