National Geographic Glow in the Dark Human body model comes with 21 organs, muscles, and bones. Kids can remove all of these parts with the included tweezers, then put back together. Bones glow in the dark. Great Holiday gift for any age. Includes an in-depth learning guide that makes learning the human body easy and fun! Makes a great STEM gift for both boys and girls. Delight your loved ones with a holiday gift that adds sparkle and magic to their seasonal celebrations!