ergonomic steel chisel scaler uses a rapid, hammering action  to quickly chisel away the material you’re removing. powered unit  The ergonomic design lets the operator stand upright, eliminating backaches, while the high-strength tubular handle and soft foam hand grips provide operator comfort. This chisel scaler removes up to 200 square feet per hour of 4″ ceramic tile set in standard thin-set. The quick-change, hardened steel tool chuck accepts dozens of accessories, and the extra-large pistons provide hard hitting action. Requires 12-15 CFM at 90 PSI