Whatsapp 9869309199 Pixart 3360 flawless sensor 32,000 dpi, LK optical switches with ultra low 0.2ms latency. (Optical switch > mechanical switches), forever immune to double click issue cuz of being optical switch. 0.2ms click latency due to being optical. Absolute bang for every buck. This is the “fps” variant. The non fps variant has different sensor and no optical switch. So dont confuse