ThinkFun Fifteen Puzzle - Classic Puzzle Game, Perfect for Travel, Can Fit in Your Pocket For Age 8 and Up HIGH QUALITY - Stainless steel construction, comes with leatherette travel case. AWARD WINNER - Parents' Choice Silver, Parents' Choice Holiday Guide, Parent's Guide Children's Media Award and more. CLEAR INSTRUCTIONS  Easy to learn with a clear, high quality instruction manual. You can start playing immediately! DEVELOPS CRITICAL SKILLS - Builds logic and problem solving skills through fun gameplay. COMES WITH MULTI-LEVEL CHALLENGES - The Fifteen Puzzle comes with 31 challenges.