A clear case shows the plain back of the device. Put a printed card behind it and the back becomes a small picture you can swap whenever you like. This set gives you 20 of those pictures, sized so they lie flat between the device and the case.
The designs come in five groups of four. Botanical has ferns, wildflowers, eucalyptus and a green garden arch. Cozy Reading has a stack of books under a teacup, a rainy window, a gingham tea card and a full bookshelf. Dark Academia uses gold on navy, oxblood and forest green: moon phases, a candle over an open book, an ex libris plate with a line for your name, and a wall of old spines. Pastel and Autumn round it out with bows, clouds, daisies, falling leaves, pumpkins and a rust plaid.
Two sizes are included for every design. The larger one is 123 x 172 mm for 6.8 and 7 inch readers, the smaller one 106 x 156 mm for 6 inch readers. Each is a couple of millimeters smaller than the device on every side.