Swim Caps features: These premium swimming caps are skin-friendly, and lightweight, which allow head to breathe for a more comfortable fit. They can protect children head from damage. More comfortable and suitable for your head and ear. One size fits most, high elasticity makes it super stretchy and not easy to deform. Features-Material: Silicone-Size(M):21.00X17.50X0.20cm/8.25X6.88X0.08in(Width: 20cm/7.87in, Hat Mouth: 17.3cm/6.81in)-Can protect your hair from chlorine, salt water, keep your hair packed when swimming, have a clear vision -Good hydrodynamic design helps you swim faster with less water resistance, help freely enjoy swimming, bathing.-Has extra room for the ears covering, add a protection for ears, and limit the water flow entering ears.-Features great elasticity, it is flexible enough to fit most size heads including girls, boys, toddlers.-With silicone material ensures the swimming hat extremely tear resistance and durability.