Their customer service number is 1-800-423-2567.
After it picks up there's an auto answering thingy, press 1 to place a new order.
The product name is Carpet Cutter replacement blades and the number is # 97642
Eventually a real person comes on. Order the number of packages you want----they don't sell by the case or anything like that. They'll give you a price, plus tax, plus shipping and also a confirmation number. They'll also send you a confirmation email.