Zenbooks are a family of ultrabooks – low-bulk laptop computers – produced by Asus. The first Zenbooks were released in October 2011, and the original range of products was amended and expanded during 2012. Models range from 12-inch laptops, featuring power efficient components but lacking connectivity and having only integrated graphics processors, to 15-inch laptops with discrete graphics processing unitsand optical disc drives. Most (though not all) Zenbooks use Intel Core ultra-low-voltage processors and Nvidia GPUs when integrated graphics are not used. Asus introduced new models with touch screens to take advantage of Windows 8 after its release in late 2012. Most models drew comparisons to the Macbook Air. The most recent release in the Zenbook line is the upmarket Zenbook Infinity UX301 series.
Asus designed the Zenbooks with brushed aluminium chassis and high rigidity, rather than plastic, the usual laptop construction material. A pattern of concentric circles on the lids is said to represent ripples in water and represent the "zen philosophy" that designers wanted to portray when creating the laptops. Zenbooks have been generally well received due to their chassis design and appearance as well as the high quality screens used in later models. However, the touchpad software was found to be erratic, particularly on the early models and some of the models received criticism for their high prices. Some models (such as the UX32) suffer from lockdown when the lithium polymer battery cell gets drained or discharged below its recommended threshold, for example if the device is left on and unattended. The result is that the charger will fail to recharge the battery even when plugged in, leaving the machine in a near-complete unresponsive off-state. The machine can often be revived by pressing the power-on key for 10 seconds, whereupon it will start recharging.