Every time I have been in Harbor Freight stores, they have had only one size blade. It fits the cutter someone showed in a previous post. You might look up the store on line and phone and ask them about the size and also the correct price. I suspect that might be a pricing error.
Originally they were $1.49 per package of 2. The price went to up $1.99 per package. Then they put them on sale for a period of time for $1.49. If you find them it would pay you to buy as many packages as you can. I have a good stock of them that I will be glad to share with anyone who does not have a H.F. store in their area.
June in Cincinnati