Height Adjustable 24" Diameter x 2" Thick Solid Maple Platform for Super Fast Rebound Solid Maple Platform has 10" Of Height Adjustment Fits I-Beam from 4.0" Wide to 6.25" Wide. Customized Wider Sizes Available Speed Bag Not Included - Firstlaw Fitness Speed Bag Swivel Included 100% MADE IN THE USA - LIFETIME WARRANTY The Firstlaw Fitness I-beam Speed Bag Platform is the most rigid speed bag platform on the market. The mounting assembly is ¼” steel and the 24” platform is solid maple. The platform has 10” of height adjustability. For use on steel I-beam from 4.0” wide up to 9.0” wide. IBSB-1 is for I-beams 4.0” wide to 6.25” wide IBSB-2 is for I-beams 6.5” wide to 9.0” wide Custom wider sizes are available. Our Speed Bag Platform includes the Firstlaw Fitness Speed bag Swivel and all mounting hardware. 100% Made in the USA Lifetime Warranty