The plastic 'Double Sided Waterproof Silicone Fly Boxes' from Richard Wheatley are sturdy, with a silicone interior that provides a durable backdrop to hold flies tightly. Inside there is a choice of Easy Grip or Easy Slit. These double-sided fly fishing boxes have clear lids that are easy to see through to so you know what you have. Sizes available, with approximate dimensions L x W x D and flies (Easy Grip / Easy Slit) are: Very Small - 106mm x 76mm x 34mm (98 / 120 flies) Small - 124mm x 100mm x 44mm (180 / 180 flies) Medium - 152mm x 100mm x 44mm (220 / 216 flies) Large - 186mm x 116mm x 40mm (312 / 280 flies)