4 pc. Bi-Material Screwdriver Sets has a black oxide coating that provides a more precise fit and reduced fastener stripping and cam-out. The polypropylene material and ergonomic shape of the handle offers twisting force for three different applications; a speed-zone for quick rotation, a torque-zone for added grip in heavy torque applicationsImproved durability & fit - black oxide tip provides improved durability and grip without compromising tip fitmentQuick rotation control - speed and precision tactile zones provide quick rotation control for efficient run down and precision tasksPrecision tactile zone for tasks requiring more rotation control