The H2S Recessed Heavy Bag Ceiling Mount is designed for any room with an unfinished ceiling and exposed joists and can hold up to a 150 pound bag. For heavier bags, you will need the spring upgrade, item BB-MH0175. This unit has the H2S™ mechanism above instead of below the mounting flange, raising the height of your bag another four inches over the Standard H2S™. Exposed beams can be up to 24 inches apart. Mounting Hole Centers: 24 in. Dimensions: 2"W x 26"L x 6.5"H Weight: 10 pounds Includes hardware for mounting to wood beams and joists.