Stainless steel balls and frame with nylon wiresIdeal for physics gadget, stress killer, great gift idea, stress killer, desk decoration, Newtons ballUse forHigh quality Newton cradle 5 balls for office, experimental classroom of science, science fair decoration, perfect for birthday, holiday, party, wedding day etc.FeaturesDemonstrates the maintenance of mechanical energy intelligence development: A good argument for Newton's Movement Law and the starting point of physics (Newton's Motion Sets). For each action there is an equal and opposite reaction. Inspires us to better understand the concept of impulse retention.Contents:1 x Newton's CradleSize: L: 7.1 x 4.7 x 7.1 inches weight: 2.5 pounds (including packaging)Notes:2. If you receive the item, please take the balls out one by one or the balls can confuse at the top. It is suggested to set horizontally.3. Package is disassembly and transport, need to install yourself, the installation time may be a little deviation specifications, please be patient.4. Use under adult supervision. Do not put the small parts of the toy in your mouth to prevent the baby from swallowing it.