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 comes with a comprehensive accessory package for experiments in linear motion. The track length is 150 CM and it is straight to better than 0.1 MM throughout. An instructional manual is included. NOTE: This item requires an air source, item QAS001 or QAS001V, and a digital timer with photogates, item DTPHG1 (not included). more detailed description available upon request. Shipping weight: 16 Lbs., dimensions: 64" x 7" x 10".