It is convenient to measure the angles of the drill bit to ensureS the accuracy of drilling the depth can be measured by flipping and Makes adjustments for height and we also supply you 3-10mm Drill bit limit Rings which is more convenient to operate. Fast and accurate measure, easy to repeat position. Loosen the fixing screw to quickly adjust the required size, it can also completes repeated positioning of the same height.Follow our photos to show how operate Double-sided scale degrees are more convenient . Fast and accurate positioning, easy to repeat positioning, Drill depth measurement, Drill Angles Reference, Flipping chip height measurement, height measurement. Selected from Metal, not easy to wear, durability