1. A new kind of shockproof case for carrying amplifiers. 2.Strong aluminum alloy frame for strengthening the structure.3.Ball corners for protecting the case against damage during transport.          4.Casters for easy-taking.They are fixed to a wood board of 15mm thickness .    Feature:1. An iron frame is equipped as the interior part , which can make the case much more stronger.2. Springs connect the iron frame to the shell case.3. Two lids can be put inside the case in the space between the shell case and the frame.