US Patent 9517398 Extra-long air-water sandbag

An extra-long air-water sandbag includes an inner bladder and an external bag. The external bag is a bag to hold the inner bladder and covers the external of the inner bladder. The inner bladder further includes an inner and outer layer container set which includes a gas container and a liquid container, and an extension layer gas container which is a bladder for containing gas and housed at the top, bottom or top and bottom thereof to increase the total length of space of gas container of the punching bag. As the length of gas container is increased, combat training for the feet is hence achieved.