Amazon’s health and fitness tracker is now available for anyone to purchase. 

The Halo band costs $99.99, provides access to the Halo app and comes with a six-month subscription to accompanying health services. Amazon launched the device in August, but it was only available to consumers on an invitation-only basis. 

The device competes with the likes of the Apple Watch and devices from Fitbit. Amazon designed the Halo to provide a comprehensive view of users’ personal health and wellness by incorporating features that measure body fat percentage, activity levels, sleep and a tool that tracks how users sound to others by listening to the tone of their voice. 

Early reviews haven’t been favorable. The Washington Post, for example, said recently that the “Halo collects the most intimate information we’ve seen from a consumer health gadget — and makes the absolute least of it.”

Amazon said it introduced improvements to the Halo based on feedback from invite-only users. Among them are a new feature called insights, which shows users trends or patterns based on their activity and sleep, as well as in their tone of voice, such as “peak periods of positivity and energy.”

It’s also rolling out on-demand workouts from a range of popular fitness brands, such as Orangetheory Fitness, Aaptiv and Openfit. 

The Halo represents Amazon’s first foray into the fitness wearables market. Its hardware business has traditionally been focused on in-home devices, like its lineup of Echo smart speakers and Fire TV streaming video devices. 

Amazon was widely anticipated to be preparing to enter the wearables market for many years. Wearables give the company another entry point to learn more about customers when they’re not engaging with Amazon’s website.