Tovolo 2 in 1 Pizza Wheel

What are the different wheels for?

I think the second one is just a spare, but I’m waiting on confirmation.

This dual pizza wheel by Tovolo is ideal for slicing pizza, focaccia and more. This cool pizza tool features two interchangeable blades; a traditional stainless steel blade, plus a polycarbonate blade that minimizes scratching on non-stick surfaces. It has a comfortable ergonomic handle, while the blades that lock securely into place are also removable for easy cleaning. The cover included protects blades for safe storage.