D-ROAD Ultra-smooth Gear 3D Magic Cube 3x3 Cube Puzzle, White Tension adjustable. 3d gear is designed art beats nature. Rubik's cube designer, 26 blocks of the cube is a gear, meshing. Unlike ordinary 333 cube, with four water chestnut as the center fixing the whole cube. Difficulty level:medium. Great choice for both beginners and cube game fans. This product contains small parts, children below 8 years old needtheir parents to play with them, so as to avoid suffocation.