The commercial launch of the iWatch will be in October, says Reuters.
The screen is said to be 2.5 inches on the diagonal and protrudes slightly from the band.
The interface will be touch and the charging will be wireless.
Messaging and voice will require a paired iPhone. The iWatch will only be compatible with devices running iOS.
Apple is said to be planning to ship 50 million of the devices in the 12 months after launch. Quanta is said to be responsible for 70 % of the production.
Smart watches have been launched by Samsung, Sony, Motorola and LG with little market success.