So these KISSWILL rotary blades are seriously sharp and perfect for when your current blades start getting dull! The 10-pack gives you plenty of replacements so you're not constantly reordering. They're specifically designed to be compatible with all Fiskars 28mm rotary cutters - just pop out the old blade and slide this one in. Made from high-quality SKS-7 tungsten alloy tool steel that stays sharper longer than cheap blades, and they go through four individual sharpening stages for that perfect edge. They cut through multiple layers of fabric, paper, leather, vinyl, cardboard - pretty much any crafting material you throw at them. The 28mm diameter and 0.3mm thickness are standard for most rotary cutters, and they come in a protective storage case to keep them organized and safe. Seriously, if you're into quilting, sewing, scrapbooking, or any kind of crafting that involves precise cutting, having sharp blades makes all the difference in getting clean, professional results. These are way more affordable than buying the brand-name replacements, but the quality is impressive - they cut cleanly through multiple layers without fraying or jagged edges. Just remember they're super sharp, so handle with care and keep away from kids. Using a cutting mat will help preserve the blade life too. Great value for serious crafters!