The Firstlaw Fitness I-Beam Rolling Punching Bag Hanger is perfect for mounting a heavy punching bag to your steel I-Beam. Designed for heavy bags up to 300 LBS. The I-Beam Rolling Mount rolls smoothly along just about any size I-Beam and the dual brake system locks it down tight. This rolling action allows you to move you heavy punching bag out into the middle of the room during a workout, and move it back when not in use. Or super charge your workout and leave the brakes off. This will add a ton of additional cardio. The Firstlaw Fitness I-Beam Rolling Mount comes with a lifetime warranty and is made in the USA. Its the best way to maximize you workout space.