Apple has started selling refurbished iPhones on its own store for the first time.

The iPhone 6S and iPhone 6S Plus are both available in a range of colours. Prices start from $449 for a 16GB iPhone 6S, $80 less than a new version of the device.

The devices are fitted with new batteries and new outer shells as part of the refurbishment. They also come with a one-year warranty.

New revenue stream

Apple had previous sold refurbished Macs, iPods and iPads on its store, but this is the first time it has started selling its iPhones in a similar condition.

The new purchase option could be in response to Apple's sales dropping for the first time in 15 years in 2016. Sales of iPhones dropped to 45.5 million, down 5% year-on-year.

A new purchase option for the iPhone could help to drive sales of the phone in the future. It is currently unknown if Apple will be offering any other version of the iPhone as a refurbished model in the future.