Amazon’s Halo device works with a membership service with features including a tool that assesses the user’s tone of voice. (Amazon Photo)

Amazon made its new Halo health band and related subscription service generally available for purchase in the U.S. on Monday morning, following recent reports highlighting concerns about the potential privacy implications of features such as 3D body modeling to estimate body fat, and the ability to assess and provide feedback the user’s tone of voice.

The device is available for $99.99, with six months of Halo membership included. It was previously available for $65 on an invitation-only basis under an early access program. 

In a review published last week, the Washington Post called Halo “the most invasive tech we’ve ever tested.” This prompted U.S. Sen. Amy Klobuchar to send a letter to Alex Azar, the U.S. Health and Human Services secretary, expressing “serious concerns regarding recent reports on the data collection practices of Amazon’s health-tracking bracelet.”

Amazon addresses privacy concerns in a white paper. “We’ve built strict protection mechanisms for customers’ most sensitive data, like Body and Tone, by storing it locally on the customer’s phone by default, when possible, and deleting it after it’s processed,” it reads, in part. “In doing so, we ensure that Tone speech samples are never accessed and body scan images are only viewed by the customer—we do not use either dataset for improving our machine learning algorithms.”

In a statement, Amazon notes that Body and Tone are both optional features, not required to use the product. The company says it’s reviewing Klobuchar’s letter and is in touch with her office to address any questions.

Among other safeguards, Halo users are required to establish a unique profile separate from their Amazon account, to avoid access by others in the same household.

The company says it has added new features based in part on feedback from early users, including on-demand workouts and “Insights” feature that can ‘connect the dots by highlighting interesting trends or patterns and offering next steps to better understand or change them,” writes Melissa Cha, vice president of Amazon Halo, in a blog post.

The associated membership enables many of the signature features of the Halo service for $3.99/month. Amazon says the device and app will continue to track basic metrics of sleep time, heart rate and steps if someone decides not to renew after the six-month membership included with purchase.

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