This adapter lets you take advantage of the ratcheting action, added reach, and controlled torque of a Yankee-style spiral screwdriver by adapting it to any 1/4" hex bit. It accepts bits that have plain or grooved shanks and has an integral rare-earth magnet to securely hold ferrous screws.
Available in three sizes. The adapter for Yankee screwdriver numbers 133, 135 and 233 has an adapter size of 5.5mm (7/32"); the adapter for Yankee screwdriver numbers 30 and 130 has an adapter size of 7mm (9/32"); the adapter for Yankee screwdriver numbers 31 and 131 have an adapter size of 8mm (5/16").
A simple and inexpensive way to expand the capabilities of an already versatile tool.