TechPowerUp posted a review on the ROCCAT Kone XP Air
A quote from the article:
Aside from making the Kone XP wireless, the Kone XP Air also comes with a dock for convenient charging. At 98 g, the Kone XP Air doesn't weigh any more than the wired version, and promises to deliver up to 100 hours of battery life. Of course, PixArt's PAW3370 sensor, 29 button functions, and optical main button switches are still on board, too.ROCCAT Kone XP Air Review