The Berkley Ball M. System With Fish F. Holder is available in two sizes and has an overall height of 21cm. It is made of fiberglass-reinforced nylon (20/80%), providing durability and resistance to the challenges of fishing. The 40mm round ball is coated with TPE, providing comfortable and grippy support. The fasteners are made of 304 grade stainless steel, which means they resist corrosion. This set is designed specifically for fishfinders from popular brands, making it a convenient and versatile addition to your fishing equipment.