?Worry-free Guarantee?COLIKES promises 18 MONTH AFTER-SALE SERVICE ( return for a new one or full refund).Please contact us if there exists any problem with the keyboard and mouse.COLIKES is conmmitted to satisfy your needs.HOW TO CONTACT US 1. CLICK OUR STORE NAME "COLIKES-US" 2.CLICK THE "Ask a question". ?Smart Energy Saving?COLIKES wireless mouse and keyboard has the function of automatically entering the power-saving state,plus ON/OFF switch to help conserve battery use, you can go for months without the hassle of changing the batteries.The keyboard requires one AAA battery, and the mouse requires two. ?Wide Compatibility?Wireless keyboard mouse combo can work with your PC, Desktop, Laptop or Notebook. Compatible with Windows XP / Vista / 7 / 8 /10 operating systems; simply plug in to your laptop or desktop computer and begin using. ?Comfortable & Smooth Typing?The design of this keyboard and mouse wireless creates a comfortable typing experience thanks to the low-profile, quiet keys and standard layout with full-size F-keys, number pad, and arrow keys.The ergonomic tilt angle offers a better typing position to reduce the pressure on your wrist and increase comfort. ?3 DPI Levels for Gaming and Work?The optical wireless mouse have the 800/1200/1600 DPI allows you to track it more smoothly on a variety of surfaces.Usually 800/1200 DPI for office, DPI 1600 for entertainment like gaming at home. ?Reliable Plug and Play?Advanced 2.4 GHz wireless connection delivers the reliability and speed of a corded connection with wireless convenience and freedom up to 33 ft away,so you can forget about drop-outs and delays and you can take wireless keyboard and mouse wherever you use your computer(USB receiver is in mouse’s battery compartment).