Solid Material: This hand twist drill is made from high quality alloy drill and HSS material bits for durability and long service life. Widely Used: Mainly for drilling wood, beads, resin, , ox horn, amber, olive nut, PVC, walnut, plastic, beeswax, acrylic and other materials; DOES NOT fit to drill hard material: stone, iron, steel, glass. Precise: The Spiral Drill Set comes with 25 different minisize drill bits. Portable and Easy to Use: Pen size design, easy to carry and storage.Just push and drill spins automatically without any use of batteries. The hand spiral drill is useful for precision drilling, tool making, model drill, engraving as profession or hobbies.Precise, accurate and efficient, to be used to drill wood, plastic, rubber and many other soft materials.With a wide grasp range chuck from 0.3mm to 3.6mm for purposes. Material: Alloy(drill), high speed steel(bits) Color: Black Chuck Grasp Range: 0.3-3.4mm Drill Bits: 0.5mm(20pcs), 0.6mm(20pcs), 1.0mm(12pcs), 1.2mm(8pcs), 1.5mm(8pcs), 1.8mm(8pcs), 2.0mm(8pcs), 2.35mm(8pcs), 3.0mm(8pcs) Drill On: Wood, plastic, rubber, etc Package Contents: 4 x Hand Drill 100 x Drill Bits Note: Please gently to use the smallest hand spiral drill bit,as it is like a needle which is easy to be broken. Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.