Playing NOVAG SAPPHIRE runs on 4 AAA batteries and is simple to use compared to other chess computers. The Manufacturer rated it at ELO 2393 USCF but realistically it plays at around 2100 SSDF, therefore the USCF Manufacturer rating is about 100 ELO points too high.
The NOVAG SAPPHIRE has 7 different types of levels and 56 unique time controls comprised from Tournament, Average Time, Sudden Death, Fixed Depth, Analysis, Novice and Find Mate levels. In addition there are also User Programmable Time Controls which make the level choices virtually unlimited.
This is a great chess computer and a lot of fun to play against.