Pocket Brainteasers is one of Thinkfun's most fun new stem toys for boys and girls. Each puzzle games has varying levels of difficulty, from beginner to expert, and is one of the best gifts you can buy for kids who like smart games and a challenge. Spill the four T's out and challenge yourself to fit them back into a smaller frame. Brainteaser A-Ha! 4-T Puzzle 5 Pc Set is for ages 8 and up. Pocket Brainteasers are made with high quality components and come with very clear and easy to understand instructions - you'll be able to play within minutes of opening the box. Like all of Thinkfun's games, Pocket Brainteasers is built to develop critical thinking skills. Playing through the increasingly difficult puzzles will improve logical reasoning and critical thinking skills, all through fun game play.