I will also add that the Olfa brand blades are just not that great. I too have had great luck with the blades from Amazon. I was made aware of the inferior quality of Olfa Endurance blades after purchasing them and they did not last. Numerous attempts were made to Olfa by both mail and email. I even sent them my slightly used Endurance blade so that they could see how the blade just did not hold up. Never heard back from Olfa. I will be purchasing the off brands from Amazon. They are more affordable and last just as long as other brands.