Apple's smartwatch collection will range in price from $349 to $17,000 (£299 to £13,500 in the UK) depending on the metals they are made from and the straps they are bought with.

The larger 42mm (1.7in) models of the Watch will cost about $50 more than than the 38mm (1.5in) versions in the lower-priced ranges.

Apple also revealed that the devices are due to go on sale on 24 April.

Rivals' smartwatches have only seen limited sales to date.

A press event held in San Francisco held few surprises about the wearable tech beyond the fact that the mid-range stainless steel edition would start at $549 and go up to $1,099 in the US, and from £479 to £949 in the UK including VAT.

There had been speculation that Apple would seek a bigger price gap between the model and the basic aluminium-based Sport-branded version - something that would have restricted its appeal.

"Apple's pricing demonstrates the confidence it has in the new Apple Watch's functionality, design and consumer appeal," commented Ian Fogg from the consultants IHS.

Apple's website lists a total of 38 models, which might pose a challenge to how it markets them.

BBC News