Amazon.com Inc. introduced a wearable fitness gadget called Halo, entering the market for health monitoring devices dominated by Apple Inc. and Fitbit Inc.

The Halo wrist band uses artificial intelligence to monitor a range of personal wellness metrics, from physical activity to sleep and even mood. The device’s features include 3D scans for body fat and voice-tone detection to analyze emotion. The Halo will also come with an app, and users will be able to connect their accounts to third-party programs to further monitor weight and health.

“Despite the rise in digital health services and devices over the last decade, we have not seen a corresponding improvement in population health in the U.S.” said Maulik Majmudar, Principal Medical Officer for Amazon Halo, in a statement.

The company is offering invite-only early access beginning Thursday with an introductory price of $64.99 that includes six months of the service for free.

Fitbit’s shares slipped slightly after the announcement. They were little changed at $6.44 at 9:53 a.m. in New York.

--Bloomberg News