Lenovo has never stinted on the ThinkPad X1 Carbon, its flagship thin-and-light business laptop. This year the company has expanded the X1 range, which now includes the modular ThinkPad X1 Tablet and the convertible ThinkPad X1 Yoga with OLED display. The ThinkPad Carbon X1 has also had an upgrade, the fourth-generation version being "the world's lightest 14-inch business ultrabook," according to its maker.
Lenovo ThinkPad X1 Carbon (4th Gen) review at ZDNet
Lenovo ThinkPad X1 Carbon (4th Gen) review at ZDNet