wlmouse BEASTX Wireless Gaming Mouse - Purple - Color: Purple - Accessories: USB cable, instruction manual, replacement parts - Model Name: beast X The weight is 39g (actual measurement), and it supports the talked-about 4000Hz polling rate. The latest PAW3395 sensor is used. It didn't fit my hand, and I switched to another mouse immediately, so I think the usage time is probably around 10 hours. This is just an estimate. I purchased it new at the regular price from Device Armory, not as a used item. Thank you for viewing. Also recommended for those who like gaming mice such as Pulsar, Logitech, Razer, Finalmouse, etc.