The C&F Design 5-Row Large System Foam Insert (FSA-3505) is the ideal accessory for organizing your large nymphs, streamers and salmon flies. Compatible with FFS-L1 or FFS-L2 boxes, it uses Micro Slit Foam technology for perfect, damage-free fly tying. Thanks to the Foam Changer, this insert offers unrivalled organizational flexibility and can also be used as a replacement foam for other Large watertight cases. An essential choice for anglers targeting big fish or practicing in demanding conditions.