Megapro 151NAS 15-In-1 Original NAS Driver Blue/Yellow. The 15-In-1 Original (NAS) Driver Blue/Yellow is our Original bit load driver, and is our most popular. Loaded with seven double end professional quality bits, this assortment provides the 14 most popular tips for driving screws. The shaft opening serves as a 1/4-Inch hex driver, hence the 15-in-1. The shaft opening serves as a 1/4-Inch hex driver and is made of alloy steel, while the handle is made from engineered nylon Triax resin. The EZ Guide collar helps maintain full contact between the bit and the screw for easier screw driving. The palm saver cap does not turn as you push on the cap and turn the handle to drive screws. This professional quality driver is made in the USA.