The iWatch, Apple's wearable computer, with a flexible screen and one-piece strap that snaps around the wrist and connects to an iPhone, is expected to be unveiled on Tuesday – but may not go on sale until 2015.
Though the company's chief executive, Tim Cook, is expected to show off the iPhone 6, which will go on sale by the end of this month, the iWatch, which has been rumoured for more than a year but never officially confirmed, is not believed to be in mass production.
A patent filed by Apple in 2011 and published in February 2013 suggests the wristband would have wireless links, storage and flexible display, be able to link to an iPhone, and display maps and other information.
Wearable computers that mimic the function of a watch, but also connect to smartphones to offer extra functionality, are a growing category, though still of niche interest. The research firm Kantar says only eight in every 1,000 consumers across the largest western economies, including the US and UK, own a smartwatch.
But that proportion could soar, says Ben Wood, chief analyst at the research firm CCS Insight. "This year there will be 1.3bn smartphones sold – if you can persuade even a tiny percentage to get a wearable too, the numbers get big pretty quickly."
He thinks any launch of a wearable device from Apple will overshadow existing models from companies such as Samsung, LG and Motorola. "Those have all been ugly black plastic, designed by engineers," he said. "I think Apple will look to blend technology and fashion to make it more attractive."
While photographs of the expected new iPhones have been leaked to websites in China and Australia, because their production lines have been making them by the million since mid-summer in China, nothing has appeared of the iWatch.
According to the electronics industry newsletter Digitimes, which taps multiple manufacturing sources in China and Taiwan, the device remains in engineering verification testing, a preliminary stage before it goes into full manufacturing.
Apple has shown off devices before selling them before: the iPhone was unveiled in January 2007 but went on sale in June that year; the iPad was first shown off in January 2010 but went on sale in the April.
Wood says Apple's decision to unveil the device before it goes on sale would have triple benefits for the company – maximising the surprise of its unveiling, building demand before the launch, and torpedoing sales of rival devices from companies such as Samsung, LG and Motorola, all of which announced new smartwatches this week at the IFA trade fair in Berlin.
"It's about controlling the message," Wood said of the expected gap between announcement and release. "Apple has planned hard on this, and rather than going to mass manufacturing, where there seem always to be people who will leak components for their 15 minutes of fame, they are looking for a 'wow' factor."
Multiple details have been leaked about the new iPhones – including that they will have larger, sapphire-treated screens and more rounded edges than current models.
Apple is also expected to introduce a mobile payment function into the new phones and the wearable device. The company has reportedly signed deals with Visa, Mastercard and American Express based on the fingerprint authentication system found on its current 5S iPhone. None of the companies would comment.
An Apple spokesperson said the company did not comment on rumours and speculation.
