09/25/2013 12:29 EDT | Updated 11/24/2013 05:12 EST

Amazon unveils faster, slimmer, lighter tablets with 'Mayday' 24/7 live video helpers

SEATTLE - Amazon is refreshing its line-up of tablet computers with devices called Kindle Fire HDX. The tablets are significantly faster and weigh less than the previous generation.

The 7-inch (17.8-centimetre) and 8.9-inch (22.6-centimetre) versions use displays that have more pixels per inch than Apple's latest iPad. They also come with a feature called "Mayday" that calls up a live customer service representative in a tiny video window to explain new features or troubleshoot problems. The helper can guide users with on-screen hand scribbles and even take control of the device from afar.

Amazon CEO Jeff Bezos introduced the feature to reporters Tuesday, saying it is "completely unique" and takes advantage of Amazon's large cloud computing and customer service infrastructure.