COMPACT WIRELESS KEYBOARD MOUSE COMBO LOGITECH MK220 Number pad on Keyboard 10-Key Controls for Music Limit of 5 million keystrokes (number lock key excluded) Type of key: deep-profile Resistant to spills tested in a restricted environment with a maximum liquid spillage of 60 milliliters. The keyboard should not be submerged in liquid. An alkaline battery (two AAA batteries) Mouse Sensor Technology: Optical Tracking That Is Smooth There are three buttons (left/right and middle clicks). Line-by-line scrolling Scroll Wheel: Optical, indeed Two Alkaline batteries (AA batteries) Click Here for Additional Information. COMPACT WIRELESS KEYBOARD MOUSE COMBO LOGITECH MK220 WIRELESS AND TINY With this multipurpose combination, experience the freedom of wireless. You can accomplish more work in less space with the small keyboard's number pad, which is perfect for data entry, calculations, and navigation. The mouse that is ambidextrous