Gundam Plastic model kits are manufactured by Bandai of Japan which has an exclusive license in manufacturing and marketing them around the world base on the flagship series Mobile Suit Gundam animation which aired in Japan in the year 1979, the first batch of the plastic model kit are being sold in 1980 in Japan.
They are molded in simple injection stylene parts attached on frames or now came to know as runners which must be cut out of the frame before assembly using an adhesive called plastic cement. But the current Gundam plastic model kit release in the near 1990 all feature snap-fitting. Meaning the parts can be cut out from the Runners and snap into place with each others without the use of Plastic Cement.
All Gundam models kits are typically supplied with foil stickers and sometimes dry-transfer decals to apply extra colors and markings as seen they are seen in popular media such as TV shows, movies, manga or video games. Dated since way back to the 1980 till now Bandai has release almost all the series under the Gundam animation series line. So if you count all the way back the catalog could hit up to thousands.