The 15-In-1 ShaftLok Driver Yellow/Yellow features a locking shaft that eliminates the hassle of bits falling out of the shaft when getting partially "stuck" in the fastener as the driver is pulled back away from the fastener. To lock a bit in place, simply push it completely into the shaft until it "clicks" locked. To unlock a bit, push down on the yellow button on the shaft and pull out the bit. This driver also features the patented pull-out bit cartridge, loaded with seven double-ended bits, that makes it easy to change and store bits, as well as save time and space. The shaft opening serves as a 1/4-Inch hex driver. The handle is reinforced with heavy-duty nylon, and the chamfered solid steel shaft provides a long life and durability. The shaft diameter is almost 50 percent narrower than the standard quick change chucks, allowing the shaft to reach into narrow openings. The shaft needs only a .375-Inch opening, and you can link multiple extensions together for an extra long reach. This professional quality driver is made in the USA.