Musca Fly Box - Clear Waterproof Medium Easy Grip Silicone 145x95x42 mm These waterproof fly boxes feature a Silicone rubber insert material with offset slits that hold flies firmly and maximize usable space. This box can hold the smallest of hooks with no issue, as well as larger streamer hooks. The slot sizes in this box are great for all freshwater flies, and smaller saltwater flies. Nobody likes finding an open fly box and flies all over your pack when you need them. To prevent that, these have strong latches to assure that your box stays closed until you need to open it. Color: Gray with transparant lids Foam: Chartreuse Easy Grip silicone. Dimensions: 145x95x42 mm Sold per piece.