502 is a common name for a large class of fast adhesives, and its main component is ethyl cyanoacrylate with side chains. Ethyl cyanoacrylate is an important chemical adhesive with wide applications. Ethyl cyanoacrylate is usually liquid at room temperature. The main difference between different varieties of 502 is the size of side chain, and different additives will also bring some differences to the performance of glue itself.