That's a real grade of 5.0. These are the ONLY flip flops I have ever worn that have BASIC arch support that breaks overpronation so they are perfect for people with plantar fasciitis, tarsal tunnels and just flat feet. It corresponds to the size of the shoe (many flip flops run larger than your shoe size, so you may need to order one size larger than your usual flip flop size). I took a photo with a round object underneath to show the high arch.