The punch bag is firm yet won't harm you for safety.
.Soozier Freestanding Boxing Punch Bag Stand, Height Adjustable, with Fillable Base, Absorption Springs, Suction Cups | Aosom Canada A large base keeps the balance when in use, with suction cups to keep in place on the ground. The base can also be filled with water or sand, making it heavy when full and easy to carry around when empty. It is fitted with powerful shock absorption springs, which allows the punching bag to spring back into place, everytime - giving you an effective and full work out.