WP APEX PRO 6500 Cartridge Kit 24+ 200-390 Duke 401 Svartpilen & VitpilenAPEX PRO 6500 CARTRIDGE Adjustable spring preload Adjustable rebound damping Adjustable compression damping Open cartridge technology Greater stability Improved damping behavior Improved and calmer ride Greater comfort Front fork springs need to be ordered separately. Fork Spring Option New fork springs are required when installing the 6500 kit. We give you the option to add springs to your order or proceed without them. We use genuine WP springs with