The Bugaboo Donkey 3 Twin extension set complete gives you the freedom to transform your Bugaboo Donkey 3 Mono into a side by side twin stroller. Combine this box with the Bugaboo Donkey 3 base to create a complete stroller for two children of different ages or the same age. This extension set contains a seat/bassinet frame, seat fabric complete, bassinet fabric complete, carry handle, sun canopy fabric, canopy wires, canopy clamps and a rain cover.