Designed for the mobile professional the X Series is a miniature laptop from Lenovo. Based on the Centrino platform, the X Series is now considered outdated, however, it was never engineered to be the fastest or most advanced. Built to be small and versatile the X Series comes with either a regular or low voltage Core 2 Duo, and a small 12.1" screen. Starting at just 2.7 pounds the X Series can last up to 7 hours on a single charge, which is even more impressive considering it is now approaching its end of life. The basic X series laptops are the X61 and X61s, the difference between the two is the addition of low voltage processors the X61s includes. More recently the X200 and X300 have been added to the series, bringing performance and portability to the next level.