Wheeler Engineering Precision Micro Screwdriver Set The Wheeler Engineering Precision Micro Screwdriver Set features high quality, chrome plated steel bits to hold up to heavy use and the comprehensive 58 piece set meet all of your precision screwdriver needs. The set include a handle that extends from 3-A 3/4" to 5-A 1/2" and a 5-A 3/4" flexible extension shaft to get you into those hard to reach places.