The new iPad Air is now available for purchase in an initial 42 countries, including the U.S., the UK, Canada and China.

Apple has officially announced its iPad Air last week and the big launch day has finally arrived, with the tablet going on sale on Friday, Nov. 1.

The fifth-generation iPad is thinner and lighter than any of its predecessors, hence the renaming to "iPad Air." The new full-size tablet from iPad is available in silver/white and gray/black color options and sports a $499 starting price tag for the 16GB Wi-Fi-only model. The 16GB Wi-Fi + Cellular variant, meanwhile, goes up to $629.

The new iPad Air boasts a 9.7-inch Retina display, packs Apple's new 64-bit A7 chip, sports a 5-megapixel camera and will reportedly last for up to 10 hours on a single charge. The slate weighs just one pound.

With an initial launch in 42 countries, supplies of the new iPad Air seem to be tightening already in some of Apple's online and retail stores. According to a MacRumors report, the higher-capacity models, specifically the 12GB and 64GB Wi-Fi + Cellular versions and the 128GB Wi-Fi-only models, are showing the biggest signs of weakening supplies in some countries.

The Apple-centric website claims that a number of countries now list the aforementioned models as shipping in 5 to 10 business days. Considering that it's barely launch day, supplies may become even tighter soon.

"Apple's U.S. online store continues to list delivery dates of November 4 for new orders of all models, while those looking to use Personal Pickup to order their devices online and pick them up today at a nearby U.S. Apple retail store will find that supplies are beginning to dry up with increasing combinations of models and stores now listed as 'Ships to store' rather than 'Available today,'" notes MacRumors.

Outside of the U.S., Apple's online stores are apparently listing shipping estimates instead of delivery estimates. The iPad Air is obviously a popular tablet already, but it remains to be seen whether Apple can keep up with demand.