Material: Made from high quality environmentally friendly thickened PVC material, it has been rigorously tested for toughness to ensure its durability. Suitable for arm circumference between 18-30cm, ideal for Family Swimming Tool, provides extra safety when learning to swim, ideal swimming aid for beginners, adults. The size of the arm bands was 18 x 23cm before inflating. And its height woud be 15 cm and diameter 24 cm after inflating, the inner diameter could be adjusted the air you blow in. Easy to use & deflate, the float roll up sleeves come without scratches. Mouth to blow or inflate with a pump. You can easily put them on and take them off. If you don't use them, just exhaust the gas and fold them up which will not take up place. Swimming armband has a double airbag design, which provides double protection for the swimmer. Best gift for Family Swimming Tool, you and your family will have a happy water play fun time with our inflatable water armbands. Makes your summer more colorful and cheerful. Please note that you should inflate the bands to suitable size or it will make swimmer uncomfortable.