What we do and do not know about the Apple Watch

Apple is holding a presentation in San Francisco on Monday where it is expected to release details about its upcoming Watch.

Here's what we know about the wearable device so far:

When is the presentation?

The presentation will be held at 5pm GMT and you can watch a live stream over on the Apple website.

What can the Watch do?

Apart from telling the time (obviously) the Apple Watch will be able to send and receive texts and emails, give directions and support notifications from other apps. Siri also comes as standard. However, a lot of the features will need to be synced with an iPhone to work.

The Watch will also feature Apple's health app (measuring heart rate, distance travelled etc), as well as the latest Apple Pay technology. So you can buy a sandwich without having to get your wallet out and then calculate how long it will take you to burn off the calories.

How does it work?

The Watch's functionality is controlled by the Digital Crown - which appears to be a "cross between a click wheel and a compass" - allowing the user to scroll, zoom and navigate.

What will it look like?

There will be three editions of the watch - the Watch, Sport and Edition - in two different screen sizes - 38mm or 42mm - from a choice of six colours.

How long will the battery last?

Poor battery-life has been one of the biggest problems with other wearables. Apple CEO Tim Cook has previously said the Watch should be able to last at least one entire work day. The battery will be charged by a magnetic system - as seen in the picture above.

What we don't know

• How much it will cost - it's expected to start at $349 (£230) but will be more expensive for the luxury editions.

• When it will be released - although a date in April is rumoured

• How successful it will be - only time will tell

More: How to choose your Apple Watch size