2.4GHz WIRELESS CONNECTION - Using advanced 2.4GHz wireless technology, plug and play, no additional drivers required. Signal transmission stability, working range up to 33ft. (The USB Receiver is inserted in the battery compartment of the keyboard.)ERGONOMIC DESIGN - Integrated ergonomic tilt provides comfort which helps reduce strain; The great spring action and comfortable key sizes respond quickly, improving your work efficiency, great for those working on spreadsheets, accounting files or financial applications.ANTI-SLIP AND PORTABLE DESIGN - There is four non-slip mat on the back of the number keyboard, which prevents it from sliding around your desk when in use. This sturdy number pad is easy to take with you, so you can work confidently and quickly-wherever and whereUNIVERSAL COMPATIBILITY - Lefon wireless number pad works with PC, laptop and desktop computers that have Windows 2000 / XP / Vista / 7 / 8 / 10 systems. The wireless 18-key numeric keypad is Not fully compatible with Mac OS.Specification:Power Supply: 2 * AAA Battery (Not included)colour: blackMaterial: ABSPackage Contents: 1 x Wireless Numeric Keypad1 x Wireless mouse1 x 2.4G Wireless USB Receiver1 x user manualOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.