What's the name of atp International Men's Tennis Challenge?

ATP Challenge, known as ATP Challenge Series before the end of 2008, is an international men's professional tennis championship series.

ATP World Tour is the highest level, ATP Challenge is the second level, and ITF Men's Tour is the lowest level. The ATP Challenge is managed by the International Men's Professional Tennis Association. After winning enough points in the ATP Challenge, you can participate in the lucky draw of ATP World Tour qualification.