Features: 1: NEW COLORFUL DESIGN , STYLISH AND SILENT Logitech M221 series have added blue, green, pink and white. The simple design continues to make the mouse more fashionable and energetic. 2:ENJOY THE SOUND OF SILENCE, OVER 90% NOISE REDUCTION Get all your work done without missing a beat or disturbing those around you. Silent Mice have the same click feel without the click noise – over 90% noise reduction. With the same click feel and over 90% noise reduction on the click sound, enjoy a quiet experience for you and your neighbors. 3:SMOOTH AND STABLE TRACKING Using Logitech's advanced optical tracking technology, with faster click and response capabilities, making web browsing easier and smoother. 4:SIMPLE. RELIABLE. STRONG. Enjoy a wireless connection up to 10m away* thanks to a plug-and-forget nano receiver. M221 SILENT features Logitech® Advanced Optical Tracking for ultra precise moves on almost any surface. 5:QUIET MARK CERTIFICATION Logitech is the first mouse company in the world to receive the Quiet Mark certification. Specification: Brand: Logitech Model: M221 Color: White, Pink, Blue, Green (Optional) Connection with computer: wireless Number of buttons: 3 Wireless working distance: about 10 meters Wireless transmission frequency: 2.4GHz Interface: USB Battery type: 1*AA battery (not included) OS requirement: For Windows10 or higher, 8, RT, 7 For Mac OS x10.5 or higher For Chrome OS For Linux Kernel 2.6+2 Product size: 99*60*39mm/3.90*2.36*1.54" Net weight: 75.2g Gross weight: 94g Inclcded： 1 X Mouse (Batteries not included) 1 X Receiver 1 X Manual