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. Fit four chair-shaped pieces together to form a single, large chair. Brainteaser A-Ha! Fifth Chair Puzzle 4 Pc Set is for ages 8 and up. The Fifth Chair comes with a pocket-sized puzzle that must be manipulated to solve and instructions. 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, Playing through the increasingly difficult puzzles will improve logical reasoning and critical thinking skills, all through fun game play.