POWERTEC 71036 Square Corner Chisel Perfect squaring of corners on hinged mortises and door-lock recesses High speed steel chisel 3/8" x 3/8" and a perfect 90-Degree;the compact chisel body, at 1"x1"x2", fits easily in your pocket Auto aligns for optimum convenience and performance Spring-loaded capacity means powerful and accurate cutting; sharp and ready to use right out of the box Durable steel construction means it's built to last