Yes. It works to cut back the rust and make the workings of the bike run smoother. It is somewhat a rust preventative but will not keep the rust away. I would recommend using WD40 as necessary. Hope this helps!
Yes and if you use it regularly on your chain it WILL prevent rust! The WD stands for water displacement. Iron and steel rust when they are exposed to oxygen and water for extended periods of time which cause a chemical reaction.. (that reaction is rust) WD40 not only removes the moisture, it also protects against it!