Class filled nylon construction for great strength and toughness.Feature:Works well on SUP or surfboard with single box.Class filled nylon makes the fin strong and tough.Designed for center fins like SUP longboard and paddleboard.Specification:Material: NylonSize: 6.5'' / 7.5'' / 8'' / 9''/ 10'' (optional)Weight: 141-295g / 4.9-10.4ozPackage weight: 145-298g / 5.1-10.5ozPackage list:1 * SUP Single Fin