I have purchased these blades on line from HF. I have yet to use them. I ordered 2 packages, but, when you order online they require you to buy $10.00 or more purchase. They canceled the first order. I then ordered 10 packages and was on back order for about a month and a half. I now have 10 packages which should last for quite sometime. Even if I have to replace more often, to me it is still cheaper than buying name brand blades, especially for me. I live in a small rural town