Rotary Cutter Blades 45mm 5-Pack by CESDes fits Olfa, Fiskar, Ergonomic cutters for crafting, Quilting, sewing, Paper, Leather, Cardstock, Holds Sharpness Lasting Longer 45mm rotary cutter blades made of durable SKS7 metal retains the cutting edge longer fit OLFA, Fiskar, contour and ergonomic tools; come in convenient storage case save time, hands, and joints; cuts comfortably and easily reducing fatigue and potentially carpal tunnel syndrome straight, clean and smooth cuts; even on layers of fabric, leather, paper and cardstock versatile: crafters, quilters, seamstresses, artisans, rugmakers, designers, home and office, workrooms and studios