M - height: 35.437.4inches (9095cm). Swim cap : free size (one size). Front cap : 2.36 inches (6cm).
Height : 3.34 inches (8.5cm). Circumference : 20.86 inches (53cm). Neck cover : 6.29 inches (16cm). If you choose'swim cap only', it doesn't matter what you select the option of size. Select anything when you choose the option of size.
Materials spandex neoprenepolyester 85% + polyurethane(spandex) 15%. Care don't use drier / wash with neutral detergent.Made in korea / kmtz(kimitiz) (a brand specializing in kids products). This item is made of spandex and neoprene, polyester, polyurethane.