Robotime-ROKR mechanical wind-up clock timer Pendulum Clock LK501 that can actually work! A stylish spring-driven wooden clock with absorbing building experience. Put the mechanism together and watch how it works. Best gift kits and hobby for holidays and quality time. Real peudulum: a gravity-swing pendulum with precise anchor escapement 3 hours ticking: it can actually work for arounf 1-3 hours when finished! Stylish outlook: appealing home decor for room or office Challenge your mind: the fun of kits building & brain teasing of mechanical engineering Perfect gift: gift for mechanical lovers or family & friends at any occasions like birthday, father's day or chirstmas.