Great for solo training: Whether you're a beginner or an expert, our soccer volleyball training aid makes it easy to practice arm swing techniques and throw multiple throws in a row. No need for help from others and no need to chase the ball with a rebounding bungee cord, it makes solo training less tedious and funAdjustable Cord Length: The elastic double reinforcement cord can adjust the length. For optimal serve training, we recommend finding the optimal height for your height and adjusting the length of the bungee cord by increasing the length to 86 inches or shortening it to 43 inches for swinging swivels, sets, hits Ball and Solo PracticeFITS ALL VOLLEYBALL SIZES: Our bags are made of lightweight and neoprene material to fit any size sports ball, be it football, soccer, or even basketball, all can be adjusted to fit all ages, from kids to teen to adultAdjustable Waist Size: Looped straps fit comfortably around the waist. It can be adjusted to fit different waist sizes up to 43 inches