These Mini DNA Molecular Kits provide an easy to understand introduction to DNA structure. They comprise of abstract shaped colour coded parts to represent the nitrogenous bases pentagonal sugar and pyramidal phosphate component parts present in the DNA double helix. Each component is designed so that it can only be attached in its correct position e.g. Thymine will only pair Adenine. Can be constructed on the stand or without the separators provided. The model can also be uncoiled and ""unzipped"" to produce two strands.Scale 1cm = 2 angstroms.Each kit contains all the necessary components including stand support rod and easy to follow instructions.Also available as a 22 layer model kit (B8H77213).