Specification: Product Type: 2.4G wireless Button life: more than 10 million times Battery: 1.5V Product size: 133*128*22mm Net weight: 85g Support system: for windowns98 / 95 / NT / ME / 2000 / XP / Vista / 7.0 / 8.0 Shell material: ABS Color: black,white Modulation method: GFSK Wireless keyboard power: 1 x AAA battery (Not included) Working current: 5mA (MAX) Sleep current: 0.5mA Effective distance: about 32.9FT (10M) reachability Humidity: 10%-85%RH 25 degrees Celsius Package Included: 1 x Numeric Keypad notes: 1. Due to manual measurement, please allow a difference of 1-3 cm, and the difference between different colors, please allow 3-5 grams. 2. Due to screen differences, the color may be slightly different from what you expect, please allow. Using advanced 2.4GHz wireless technology, plug and play, no additional drivers required. Signal transmission stability, working range up to 33ft 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 There is 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 where It will auto power off when not in use for 10 minutes, effectively increase the battery life Support for windowns98 / 95 / NT / ME / 2000 / XP / Vista / 7.0 / 8.0