I bought a pair of these for my wife who had Plantar fasciitis. After wearing them, her pain resolved. The fit is as expected.
The soles are rubber. The inner lining is molded like an orthotic. The shoes are very comfortable for her. She and my daughter fight over wearing them, so I bought another pair. They last a few years (3-4 years).
These are the best sandles/flip flops that you can buy.