Pivot Mount. Part Number M-1. M1 Pivot Mount brackets are designed to allow maximum mounting versatility for PolyPlanar box speakers MA-9060, MA-800, MA-7500 and MA-1610 and other popular name box speakers. Since all speakers are directional, M1 brackets allow you to point your speakers in whatever direction produces the best sound quality for the location, whether you're in a small cabin or on the upper deck of a luxury yacht. The brackets also perform exceptionally well when mounted in marinas, restaurants or backyards. Features. Simple mounting that allows you to mount speakers in difficult locations. Corrosion-proof construction. They rotate up to 360 Degrees Part Number M-1. M1 Pivot Mount brackets are designed to allow maximum mounting versatility for Pol Features. Simple mounting that allows you to mount speakers in difficult locations Corrosion-proof construction. They rotate up to 360 Degrees