The RAM-107B is compatible with the following marine GPS models:Humminbird 700 SeriesHumminbird 500 SeriesHumminbird 300 SeriesHumminbird 100 SeriesHumminbird Matrix Series (excluding Matrix 97)Raymarine Apelco Fishfinder with matching hole patternThe RAM-107B Humminbird and Apelco Series RAM mount is designed with a RAM 1.5 inch diameter patented rubber ball. Part number reflects product packaged in clear clam shell for store shelf display. For additional specifications, see components and drawings tabs.Powder Coated Marine Grade AluminumBlack Powder Coat1.5 Inch Rubber Ball