Four wooden towers, four different shape-cut pegs, and every disc has to be both the right shape and the right way up to go on. Each tower's post is shaped like a diamond, a triangle, a half-moon, or a circle, and every one of the four colorful discs that stack onto it shares that same cutout, so a disc only slides on when a child lines up both the correct shape and the correct rotation, not just drops it on loosely. Getting all four discs sorted onto their matching posts means comparing shapes across all four towers at once, since a disc that looks close enough at a glance often turns out to belong on a different post entirely. Colorful layers in red, yellow, green, and blue make finished towers easy to check at a glance, and pulling everything back off to start over is just as satisfying as building it up. Smooth, solid wooden pieces throughout make it a durable shape-matching and stacking set. A shape and color sorting game for ages 2 and up.