Solving It: There’s one empty circle and you push the colored balls around utilizing the empty space to match the color of the ball with the ring outside the circle. There’s a sponge center in the ball that allows the colored balls to slide from one space to the next when you press on them. Mixed Again: mix it up the same way you solve it. Randomly start moving the pieces around until they are all mixed up. You can strategically place the away from their “home” to make it harder. Material:Crafted with eco-friendly ABS material, non-toxic and lightweight, harmless to human and environment. Fun & Joy: Important activities to teach kids to work hard at solving complex problems and foster your kid's sense of space and enhance a child's memory.The home without a color ring is the empty one when PUZZEL is solved.