Each compartment has a lid that can be opened individually, and it&';s equipped with a holder that can hold the "3-in-1 Nail Knot Pipe," which makes it convenient for picking up flies. Large hackle patterns that are difficult to store in the Micro Slit Foam can be carried together with smaller fly patterns in one fly case. We recommend using the separately sold System Foam for trout fishing (5mm thick) to ensure sufficient clearance within the case. Dimensions: Large: (WxHxD):197x42x114(mm) Medium: (WxHxD):155x40x105(mm) Small: (WxHxD):130x36.5x104(mm)