Edge is engineered to withstand the rigors of cutting today™s heavier and thicker roofing materials 75% stronger than Stanley™s 11-983 Hook Blade resulting in fewer blade changes Cuts roofing shingles, felt paper, Tyvek®, foam board, insulation, shingles and other building materials Designed for use in fixed blade knives only ROOF callout is laser etched on blade to prevent accidental mixing with standard blades