Estimated assembly time: 1 hour. This unique set consists of 4 separate miniature models for self-assembly and is suitable for adults and children. The set includes four small models: sailing yacht, sailboat, boat, and submarine, and deals with basic elements of mechanics such as the movement of bodies, forces, and their effects. All parts are already cut out and easy to remove from the board. Each model is simply assembled like a puzzle without glue and tools, as described in the instructions with color illustrations. Engaging with the fidget is said to reduce stress, organize your thoughts, and generate new ideas. Each model can also be used as a keychain and makes a wonderful gift for your relatives, friends, and colleagues.