The C&F Design 8-Row Large System Foam Insert (FSA-3508) is designed to fit into FFS-L1 or FFS-L2 housings and tie your flies optimally thanks to Micro Slit Foam technology. It's perfect for organizing #10-18 size dries and nymphs, while guaranteeing great flexibility with the Foam Changer, allowing customization of contents. It can also be used as a replacement foam for other Large watertight cases, offering a durable and effective solution for fly management.