In order to bring a 4KHz return rate to the AJ199, AJAZZ has upgraded the main core chipset of the mouse to the new-generation Nordic 52840 chipset. Get amazing new performance with smoother tracking, faster aiming, and quick triggers with the AJAZZ AJ199 4K edition!! High-Performance Nordic Main Control Unit:. We have a flagship PAW3395 gaming-grade sensor to provide unmatched precision and accuracy with a maximum resolution of 26,000DPI. With a 4000Hz return rate, the AJ199 offers silky smooth tracking with fast aiming and better accuracy. The mouse comes equipped with a Nordic 52840 high-performance main control chipset that enables a 4K return rate on the mouse. Introducing the all-new 4K variant for the amazing AJAZZ AJ199 gaming mouse. >New-Generation Huano Blue Transparent Micro-Motion Switches. >Silky Smoother Operation With 4KHz Return Rate. >Suitable For People with Small to Mid-sized palm sizes. >Dual-Mode connectivity(Wireless 2.4GHz/Wired USB Type-C). >Adjustable high-speed 26000DPI resolution.