This air track is constructed of high quality aluminum alloy and has the advantages of being both lightweight and highly durable. Precision machining provides a smooth surface and high linearity. It includes a comprehensive accessory package for experiments in linear motion. The track length is 200cm, and it is straight to better than 0.1mm throughout. Includes activity guide. NOTE: This item requires an air source, item QAS001 or QAS001-V, and a digital timer with photogates, item DTPHG1 (not included). Air Track includes a large assortment of accessories. Shipping weight: 16 Lbs., Dimensions: 64" x 7" x 10".