A day-long battery, a 5MP camera and wifi will all be built in to Google Glass, newly released specifications have also confirmed.

Devices will be sent to those ‘Explorers’ who have pre-ordered, but Glass is not yet going on sale to the general public. In an email to the Explorers, Google confirms “The hardware and software are now ready for you. We’re seeing the first few devices come off the production line right now.”

The device provides a display worn above the user’s right eye that will connect with the internet and provide additional information about the world around them. Voice commands such as “take a picture” or “search” will also allow it to record and augment interaction.

Google warns Explorers, however, that “Instead of waiting for all the devices to be ready, we want to start delivering them to you right now. We’re producing enough for everyone but only a portion of them are ready today.”

On the new specifications page, meanwhile, Google confirmed that Glass would connect via Bluetooth to a user’s mobile phone and interact with a companion app called MyGlass that uses an interface similar to Google Now, the advanced search software.

Glass will feature adjustable nosepads an a “high resolution display” that Google says “is the equivalent of a 25 inch high definition screen from eight feet away”.

Its 5MP camera will also take video at 720p and its audio will use bone-conduction rather than conventional headphones. Of 16GB storage, 12GB will be available for recordings and pictures as well as apps, which Google is encouraging developers to write, and branding ‘Glassware’. The initial terms and conditions ban developers from putting advertisements in their apps and from charging for them. It is unclear whether this is because Google wants to ban all advertising on the device in the first instance, or whether it wants to provide all advertising on the platform itself.

Glass is the first of a new generation of wearable technologies that a number of companies such as Vuzix are also developing. Apple, Samsung and Microsoft, meanwhile, are also focusing on making watches. Some privacy campaigners have raised concerns over the technology, and at least one Silicon Valley bar has already banned them.

(First published April 16.) Information appearing on telegraph.co.uk is the copyright of Telegraph Media Group Limited and must not be reproduced in any medium without license. Reprinted here for educational purposes only. May not be reproduced on other websites without permission from the Telegraph. Visit the website at telegraph.co.uk.