This professional thin wall impact hole saw set comes with 3 mainstream sizes: 7/8 inch, 1-1/8 inch and 1-3/8 inch, fully prepared for your drilling tasks. Equipped with a robust 1/4 inch impact double end screwdriver bit, it is universally compatible with impact wrenches, lithium-ion drills, electric screwdrivers and all regular power drills, easy to install and replace. The 8-TPI thin wall design improves cutting speed by 40% than traditional bi-metal hole saws, bringing you faster and cleaner cutting results. The spring-loaded pilot bit can automatically eject cut scraps smoothly without stuck. Meanwhile, the bottom depth stop cover prevents over-drilling, which well protects electrical boxes and junction boxes from accidental damage. These hole saws are engineered to cut plastic and thin gauge metal with thickness up to 3mm (1/8 inch). A must-have tool for electricians, maintenance workers, carpenters and DIY enthusiasts for home renovation, circuit installation and pipe processing.