Qm-h Set 2x2x2 3x3x3 4x4x4 5x5x5 Stickerless Speed Magic Cube Puzzle Educational toys this is a challenging for kids and adults. For kids, it can develop their brain and logic thinking ability. For adults, it can release their pressure after work. 6 solid colored plastic sides that won't wear down, new structure design is drop-resistant and water-resistant. Eco-friendly, recyclable material product, harmless to human and environment.