Pocket 12 pc Drill Set. The vise or holder is a blue anodized 3/8" diameter barrel with pocket clip, which prevents rolling. Drill bits store neatly into the handle which is well-knurled for a perfect grip. All machined parts are rust-free aluminum, except for the chuck, which is black oxide tool steel. The chuck is pressed into the barrel so that it cannot turn and opens easilyand never binds. The chuck can take drill sizes from 0.34mm to 1.6mm. Drill bits included are: 1.6mm, 1.4mm, 1.18mm, 1.0mm, 0.96mm, , 0.91mm, 0.84mm, 0.79mm, 0.71mm, 0.64mm, 0.57mm, and 0.51mm.