This screw is made of nature wood and eco-friend water painting matetials. It's classic vintage toy will foster your kid's creativity. Perfect for birthday party toys. Colors will be more attractive when spinning. The various colorful patterns and spinning time 1-2 minutes will 100% delight your child. No batteries required so it helps safe to cultivate your kid's imagination and curiosity while providing tactile experience with natural materials. It's can help hand's muscle stiffness person relax. 1 9/16"Wx1 9/16"H