Designed For Shallower Depth Effects Products. 10 3/8" Depth On 2, 3, And 4 Space X-Racks Will Accommodate A Wider Variety Of Effect Processors, Signal Processors, Power Conditioners, Bass Amps, Line Mixers, Wireless Microphones And Cassette Players, To Name A Few, Without Unplugging Them To Close The Back Panel. Economical, Compact And Stacks On All Amps.