Methods and apparatus for executing a lighting program to control a plurality of light emitting diodes in response to at least one characteristic of an audio input. More particularly, the present invention relates to an independent suspension system for light and medium duty trailers which utilizes a flexible bladder mounted between the vehicle frame and the axle. The trailer body may also include a protective assembly adjacent to a rear door of the trailer body to protect the trailer body during loading and unloading of cargo into and from the cargo space. Furthermore, two first spacers surrounding sidewalls of the gate stack layer is further formed. A retainer ring is used to capture the venting valve within the threaded cap and a safety ring in unitary combination with the threaded cap retains the vented closure on the container.