Thank you for viewing. Stack them up, layer them on! Fun to play with in the bath! These "Koppu ga Sane" cups have rounded bottoms, making them easy to stack. You can play with numbers, pour water in the bath, and even stack them upside down for compact storage. Please understand that this is a used item that a child has played with. I will ship the items partially disassembled via Yu-Packet Plus. No returns after purchase. Thank you.