Mini electric grinding drill chuck clamping range: Dia 0.3-4mm/ 0-1/8in; shank: 3mm round shaft.
3mm shaft engraving machine conversion chuck fits all chucks.
3 Jaws can postion and hold the dril bits firmly,quick change and remove the drill bit.
Important Note: Do not operate it high speed directly after mounted on universal chuck, otherwsie rear axle will be bent.
Easy loading and unloading: this keyless drill chuck converter can go from driving to drilling in seconds, and also give you the freedom to drill with one hand, which is great for working in tight spaces.