Budget Watch Collecting/Identifying movements
Most movements have a caliber number-In most cases this will be below the balance wheel. In some cases it will be on one of the bridges, and occasionally it will be on the dial side, only visible by removing the dial. There may be several designations--It is common for the visible indications to mention the brand of the watch company, while the semi-hidden marks will tell who actually made the movement. Bulova has its own movement codes, and generally have this code on a bridge. Often however this Bulova movement was made by someone else and only minorly updated, this will usually have the maker's marks in their usual place under the balance. Ranftt.de has a very good online database of movements, searchable by number, with pictures and a varying amount of info.