Micromotor Flat Tip Drill Bit 1.8mmFlat Tip Drill Bit 1. 8mm This kit is ideal for high speed applications up to 38,000rpm. Micromotor technology allows the hand piece itself to contain the motor, whilst retaining a slender profile for easy hand grip. The high speed drill is configured for stereotaxy surgery, particularly in soft skull animals such as rats and mice. The microdrill can be secured to the stereotaxy instrument by the microdrill holder and controlled by the manipulator.