Hand Skeleton with ligaments has all the anatomically important ligaments and tendons. Model includes the interosseous membrane between the radius and ulna, removable flexor retinaculum. Now included with all 3B Scientific Anatomy models is the 3B Smart Anatomy app. This app allows users to register their 3B item to extend the warranty from 3 to 5 years plus free 1 year access to the 3B Smart Anatomy app which includes 23 Anatomy lectures, 117 interactive models and 39 quizzes.