twist drill bit: with 10x drill bit, 0.8mm / 1.0mm / 1.2mm / 1.5mm / 1.8mm / 2.0mm / 2.2mm / 2.5mm/ 2.8mm / 3.0mm. material: hand drill of aluminum shell and 2 brass cores, each core has two ends, durable. compact: suitable for, walnut, small model kit and many other diy craft. application: this hand twist drill set making handiwork, like hairpins, bracelets, necklaces, keychain, etc. double ended: this pin hand drills and copper collets is double ends, hold within 0.3-3.2mm twist drills etc., Weight: 0.110231131 pounds, Manufacturer: N\A