At One Click Purchasing, we are your reliable source for the NSN part 640-BS645 manufactured by Vt Marine Products Ltd. We carry a wide range of popular NSN items on our website, including O Ring like part number 640-BS645 which is listed with the NSN 5331991472442 for easy identification. If you are interested in 640-BS645 item, then take the advantage of our online RFQ service, or peruse our website as you see fit to find other items of interest that you may wish to learn more about.