ORIGINAL is a basic line of Casio G-Shock watches dedicated to further development of the original models from the 90s. It offers affordable watches (few thousands of Korunas) with high durability. Most popular are models GA-100 and their newer brother GA-110. An alternative to these resin Gs are more "business looking" G-Steel, or way more expensive Master of G, that are filled with technology and are loved by professional units.
* Year of issue of the original model. They look the same today, but they have a different modul.