HIGH PERFORMANCE - LOW COST - The Firstlaw Fitness Joist Mount is a great economical way to hang a heavy punching bag. The Joist Mount has a built in compression spring system that will absorb noise and vibration. Both Joist Mount 120 & Joist Mount 200 use the same chassis. The only difference is the size of the internal spring. For best performance select the one that best matches your heavy bag weight. The internal compression spring system also has a built in full 360 deg swivel.GREAT FOR LOW CEILINGS - The Joist Mount securely mounts to the side and bottom of an open floor joist. This unique mounting is ideal when you have a low ceiling.BUILT TO LAST - The Firstlaw Fitness Joist Mount is engineered to handle every style of punches and kicks.PROUDLY MADE IN THE USA - The Joist Mount is 100% made in the USA. Great For Low Ceilings Mounting to the side and bottom of a floor joist keeps the heavy bag higher than many other mounts. Our Design - Simple & Effective The internal compression spring and 360 deg swivel makes the Joist Mount a simple heavy bag mount solution. Perfect Addition for any Home Gym The Joist Mount was designed and is built in the USA. Always Built To Last All Firstlaw Fitness products are built to last.