These slim Magnetic fly boxes are thin enough to fit in a shirt pocket, yet can still hold dozens of flies with 8 compartments. Each compartment has rounded sides that allow you to easily select even the smallest flies without the need for tweezers. The magnets hold flies in place, keeping them from falling out, even when turned upside down. This box has saved me many times. Ive even dropped an open box in the water while fishing and was able to recover all my flies. These boxes are also waterproof which means you can keep your flies dry, even when wet wading or accidentally dropping them into the water. These boxes are perfect for nymphs and small streamers. Great for minimalist fishing where you dont want to take a ton of gear. Just slip this into a shirt or pants pocket, grab your fly rod and some nippers and go out and fish. Or you can put multiple boxes in your fly pack and organize your flies to type with many boxes.