The Scotty 1.5" Ball System Arms provide rugged support and versatility for attaching 7-9" fishfinders to your boat. With a 2¼"/5.7cm square fixed base and construction of corrosion-resistant stainless steel and technical nylon, these arms are ideal for use in both freshwater and saltwater environments. They are compatible with most popular electronics brands and work seamlessly with all 1.5"/3.8cm Scotty ball system accessories. UV-resistant nylon ensures durability and reliability even under extreme conditions. The easy-grip T-button allows for easy release or tightening, while the 1.5"/3.8cm ball joints offer full 360˚ rotation and 180˚ tilt for optimal positioning of your equipment.