Auralex GRAMMA-II, 15"x23"x1.75" isolation riser

Gig & Recording Amplifier & Monitor Modulation Attenuator The GRAMMA Sound Isolation Riser is an incredibly effective device that's used to float an amp or loudspeaker and yields nearly total acoustic sound isolation, resulting in a purity of tone that has to be heard to be believed! GRAMMA comes complete with a carrying handle, road-ready carpet, Studiofoam Wedges (underneath), PlatFoam (underneath), and an optional GRAMMA Gigbag. 1-2 GRAMMAs will support most amps, speaker cabinets, theater subwoofers and monitors.