Surf boots, reef boots. Can also be used for river play, etc. Regarding the size, they fit perfectly for someone who usually wears 26.5cm shoes. I think they would fit those who wear 26-26.5cm, but please consider this as a reference as there may be individual differences. Used about 1-2 times. There are no particular problems with the Velcro, etc., but please understand that they have been stored for a long time.