This exquisite and refined model gives the feel of a real-life mechanism. The Model helps people to understand the details involved in mechanical motion, through the self-assembly of motion models. The estimated time of assembly is 3-4 hours which will help kids and adult to develop logical reasoning during the assembling. Ugears 3D mechanical Model enhances attention and concentration skills as well as improving attention to detail skills. The UGears Timer has a unique roller pendulum and a lever for amplitude adjustment on its backside. It is powered by the pull of a simple office rubber band, and this can be used to set the alarm on this unique piece. It runs like a clock work ticking away in a relaxing rhythm. This beautiful meditative timepiece adds sophistication to any room! The alarm gives a pleasant pop sound after 20 minutes when it is set. Ages 14 & up. 107 pieces. Level: hard.