MaterialThe drill is made of hardened steel to ensure this drill is ready for any hobby and precision work you can throw at it, and to handle your precision builds. < p>Various SizesComes with 1 mini pin vise and 25 twist drill bits: 0.5/0.6mm (5 pieces for each size), 1.0mm (3 pieces), 1.2/1.5 / 1.8 / 2.0 / 2.35 / 3.0 mm (2 pcs for each size). The pin vise drill kit of different sizes can meet your different needs. AdjustableIt can firmly hold thin drill bits. The tightening thread (female thread) must fit the underlying metal correctly and be stable. This hand drill has an adjustable drill bit holder which matches different sizes of drill bits you use. Wide ApplicationCompact size, useful for electronic assembly, tooling, model making , winding, home renovation. This portable mini rotary drill is easy to operate with its grooved handle design, you can hold it in your hand easily and comfortably.