20 minutes Timer with an alarm mechanism is one of our most exciting models. If the alarm mechanism is set when the time runs out, you will hear a pleasant sound. The Timer has a special roller pendulum and a lever for amplitude adjustment on its backside. It is powered by the pull of a simple office rubber band. This model went through a great deal of improvements and refinements to become this beautiful piece of machinery that anyone can put together for their delight.\nThe kit has all you need for assembly: a set of high-quality plywood boards with precisely cutout parts, detailed step-by-step instructions, and additional details. The quality and accuracy of the parts is very high due to a laser cut method we employ.\nYou need no glue to put UGEARS models together, which makes watching it working and moving even more exciting. You can assemble them at home on the table. All you need is your own hands, patience, and assembly instructions.