This double helix DNA model is pre-assembled and makes a very impressive display and learning tool. Measures 25 x 8 inches, made of durable and colorful plastic and depicts a 16 base pair section built to a scale of 10cm to 1nm. The model is supported on a circular stand, which can rotate allowing you to view all of the components. The phosphate and deoxyribose are accurately portrayed and can be removed and separated for further examination, along with the individual base pairs.