This is a swim cap set for Central Sports Kids. It's a set of two, green and navy, both size L (54-59cm). Swim caps come in two sizes, and my child used size L in the third grade of elementary school. Green: Up to 25m breaststroke Navy: Up to 25m butterfly It's a good deal to buy the set if you want to complete butterfly. (We couldn't quite commit and bought new ones each time.) It may depend on the area, but perhaps because butterfly is taught in junior high school, some children from 6th grade elementary school to junior high school joined, starting with butterfly. (Butterfly is taught in the classes at my child's junior high school.) Retail price: 3300 yen Used for: 2 months each. The name was written on the green cap tag with a marker, so it has been blacked out. (See image) Thank you.