Gator GRRACKBAG4U 4U Lightweight Rack Bag with Aluminum Frame and PE Reinforcement The 4U Lightweight Rack Bag (Black) from Gator Cases provides an ideal way to carry and protect devices like effects processors recording equipment and sound modules. The exterior is made from 600 denier nylon and it has an internal aluminum frame reinforced with polyethylene. A rear flap allows easy access to the entire panel of equipment while an exterior pocket provides storage space for any accessories you may need. Both the main compartment and pocket have secure zippered closures. The bag can be carried using the soft-grip carry handle.