Quality Self Propelled Marble Roller Coaster-The laser-cut technology enables the piece operates with its clever mechanical clockwork operation. Hand crafted by the finest master craftsmen using only time-honoured traditional methods and techniques. These high quality model kits are self propelled clockwork, no battery needed. Some wax and the tools provided will make them move smoothly. Creative Activity for Brain and Memory These 3D wooden Mechanical Clockwork Puzzles require minimum of 4 hours of DIY full of fun. The puzzle activities have been scientifically proven to improve memory, relieving stress, improve visual-spatial reasoning skills and increase IQ. Perfect Gifts for Puzzle Lovers-Excellent gift for puzzle lovers to enjoy wonderful puzzle solving experience and creative design. Recommend 14 Year Old and up, small parts not for children under 3. Package includes everything you need to make this amazing model. All it requires is your time and patience. An enchanting fantastic experience to enjoy and you will be thrilled when the project is finished. Its like an Old Time Manual Toys, NO BATTERIES NEEDED. bring out the imagination for our youn Package Dimensions: 5.2 L x 31.9 H x 23.7 W (centimeters), Manufacturer: ROBOTIME