Little Treasures Cube Speed Smooth Magic Cube Puzzles, Stickered Adjustable corner cutting tension - tighten or loosen the center screw to adjust the tension Standard structure comes pre-lubricated by the manufacturer, but the tightness is adjustable If the cube doesn't fit your style, just open the center caps and adjust the screws Challenge their young mind with puzzle cubes, improves fine motor skills and dexterity while keeping them engaged for hours