The Neo Geo Pocket was SNK's first hand held video game system, released in Japan in late 1998; however, lower than expected sales resulted in its discontinuation in 1999, and was immediately succeeded by the Neo Geo Pocket Color. The system only had a retail release within the Japan and Hong Kong market.
Side by side, a Neo Geo Pocket on the left side and a Neo Geo Pocket Color
King of Fighters R-1 (I have both R-1 and R-2)
Bought on eBay for 30 euro with King Of Fighter R-1