Just got back from a visit to Harbor Freight, and I am thrilled! Yes, these are the same size blades that fit the Olfa, Fiskars, Clover and Martelli. Any and all 45mm size rotary cutters. I love that they have a smooth center hole rather than the notched hole on Olfa blades. Cuts through fabric like butter. And at $1.99 per 2-pack, you can't beat that! LOVE IT!!
Just curious, I wonder how their carpet cutter that these blades go into would work on fabric....hmm