The Mechanical Aquarium from Ugears is an ingenious saltwater fishbowl, with two pet tropical fish chasing each other around a forest of macroalgae fronds, inside of which hides another small inhabitant of the marine environment, a seahorse! The beauty, variety and intrigue of saltwater fish-keeping makes it one of the world's most popular hobbies. Perhaps you are a snorkeling or diving enthusiast and would like to be reminded of underwater adventures when you've dived a colorful reef or explored a kelp forest. Building Ugears' charming and unique wooden models, brain teasers and 3D puzzles has become a popular hobby for thousands of people in 85 countries across five continents. Now you can combine these hobbies in a single model! The Mechanical Aquarium has 325 pieces, is rated "Medium" level, and has an estimated assembly time of 6 hours. As you build the wooden aquarium, you will learn about the action and interplay of drive gears and driven gears in gear sets, the function of pendulums, and about spring-action mechanisms. You will experience the satisfaction of building something beautiful with your own hands, without need of glue or special tools. Everything you need for this fun DIY project comes right in the box: high quality plywood boards with precision laser-cut pieces that you snap out then snap together, the metal spring that powers the mechanism, and of course a set of detailed, illustrated instructions in 11 languages.