It is a Portable Tools/Hand Drill/Alloy Tools/Spiral Hand Push Drill. Chuck Diameter: 0.4”. Material: Pure Brass Hand Drill & High Speed Steel Twist Bits. Application: Mainly used for Wood, Resin, Jewelry, Walnut, Amber, Beeswax, Olive Nut, Vajra Bodhi, Beads, Ivory Nut, PVC, Acrylic and Plastic etc.