The Auralex GRAMMA (Gig & Recording, Amp & Monitor, Modulation Attenuator) is an incredibly effective device for floating an amp or loudspeaker and yields nearly total acoustic isolation, resulting in a purity of tone that has to be heard to be believed! GRAMMAs are incredibly effective with guitar & bass amps, PA stacks, and subwoofers. Auralex GRAMMA comes complete with a carrying handle, road-ready carpet, Studiofoam Wedges (underneath) and PlatFoam (underneath). 1-2 GRAMMAs will support most amps, speaker cabinets, subwoofers and monitors. Size: 23"L x 15"W x 2.75"H. Weight Limit: 300 lbs. Size: 23"L x 15"W x 2.75"H Weight Limit: 300 lbs.