A speed bag is a small, air-filled punching bag that is typically mounted on a platform. It is used primarily in boxing and martial arts training to improve hand-eye coordination, speed, and rhythm. The bag rebounds quickly after being struck, allowing athletes to practice their punches and develop timing. Speed bags come in various sizes and are often made of leather or synthetic materials. They are usually hung from a swivel, enabling them to move freely in multiple directions. Regular training with a speed bag can enhance a fighter's agility and overall striking skills, making it a popular tool in gyms and training facilities.