This Interchangeable Balldrive Set is 8" long from the tip of the bit to the end of the handle, and have 3" long steel alloy bits. The bit selection in the set was specially chosen to fit the most common hex sizes used in Thorlabs' products. Unlike standard hex wrenches, the unique hex ball design of the balldriver tip allows it to operate at angles, which is ideal for hard-to-reach places.
This Imperial set contains 7 interchangeable bits in the following sizes: 5/64", 3/32", 7/64", 1/8", 9/64", 5/32", and 3/16". 6 of these bits fit securely in the yellow handle while the 7th must always be kept in the shaft, ready for use.
To change a bit, firmly pull the bit out of the shaft. Insert the top of the bit that was just removed into the hole on the bottom of the handle that houses the bit you would like to use next. Tightly grip the handle and push the old bit into the hole, which will cause the new bit to come out of a hole located at the base of the shaft. Pull out the new bit, and slide the old one the rest of the way in.