These shoes replace my original F-Lite 230. They are heavier and more durable. I only use them in the gym. But the F 230 were the most comfortable shoes ever! PLEASE return the original F-Lite 230. A NOTICE. I always recommend people order their EU size instead of relying on US size. That has proved to be the case with this shoe. 45EU can be 10.5 to 11.5 US male. That's why I always order EU45 and it fits.