Ask for carpet cutting or rug cutting blades. Someone already pointed out that there are two blades in each packet; be sure to only put one in your rotary cutter. They kind of stick together and using two makes the whole setup not work. I find these blades to be a good value but have friends that haven't had luck with them. If you can get to a Harbor Freight store it's a great place to browse and see things that work well for quilters at great prices.