This fast, clean cutting TurboShear Drill Attachment is specialized for cutting 1/2-in. (12.7 mm) fiber cement backer board. The drive shaft of this one-hand operation accessory quickly inserts into the chuck of a corded or cordless electric drill! This versatile and economical accessory is a welcome replacement for messy, imprecise, scoring and snapping methods of trimming backer board. A wide skid-plate on the head design stabilizes cutting action for extra smooth results. This versatile shear navigates curved-pattern cuts for window and door arches and will also cut 5/16-in. (8 mm) fiber cement siding plank. The hardened carbon steel blade and skid plate ensure long uninterrupted service life. You can even rotate the tool’s skid plate to maximize acceptable cutting life. And the blade and skid plate set is also easily replaceable on the job. A sleek, lightweight aluminum cast shear head and molded drill clamp allow maximum portability and ease to go wherever the work is. The patented compact telescoping drill clamp adjusts to fit both length and width of the drill housing including smaller bodied impact drivers. Optional spacers are stored on clamp for large motor housings. The clamp collar allows the shear head to be rotated 360° and set in any position for optimum tool clearance or to facilitate easy material flow.