50 Piece, Hook Knife Blades With Dispenser, Optimized Grind Angles Deliver 2X Sharper Blade & Improved Cutting Precision, High Quality Steel For Maximum Strength In Pull Cut Applications, Optimized Grind Angles Deliver Improved Sharpness For Less Repeat Cuts, Ideal For Roofing, Carpet, Tyvek, Insulation & Other Building Materials.