Mice & Trackballs iMice 2.4ghz Wirele Mouse Computer Mouse 1600 DPI Ergonomic Mause For Laptop PC 4 Buttons USB Silent Mice 1.Silent design: the button of the mouse is silent , it will make le noise when you click, offer you a quiet environment in public places2.4 Keys: Easy to operate, the buttons with soft click make you comfortable3.3 levels DPI:suitable for different use , provide the Provide precise positioning4.Easy Installation:Just need to place the AA battery (not included), and plug USB to computer , it can use directly 1.item name:2.4G Wirele mouse2.Size:115*65*33mm3.Key numbers:4 keys4.Color:Black/Red/Gray/Blue5.Optical resolution:800/1200/ 1600 DPI6.Transmiion distance :10 m7.Power:1*AA Battery( not included) 1.1* 2.4G Wirele mouse2.1*USB Receiver Q&AQ1: Where is the USB receiverA1: The USB receiver is in the receiver slot , you need to remove the buttom cover and then you will see the USB receiver in the receiver slot