This oversize load mirror extension bracket fits the Peterbilt 579.  (This will fit any truck with the mirror brackets that have the same configuration as seen in the picture).  The mirror brackets are billet aluminum and anodized black.  With each set you receive a drivers side bracket, a passenger side bracket and 24" extension bars.  (mirrors are optional) - Mirrors can be purchased for an addtional $30 per pair.  We also have 36" extension bars which can be purchased for an additional $40 per pair.