In order to use the EKG feature on the newly available Withings ScanWatch, people have to first get the tool unlocked through a prescription from a healthcare provider — a first for EKG-enabled smartwatches on the market. Other smartwatches like the Apple Watch let people start using the feature right out of the box.

The requirement was part of Withings’ Food and Drug Administration authorization, which says that the device can track heart rhythms and detect atrial fibrillation “when the monitor is prescribed or used under the care of a physician.” The extra step of obtaining a prescription came out of the company’s initial conversations with the agency, Shikha Anand, Withings’ chief medical officer, told The Verge.

“We don’t imagine that will be true for in perpetuity or even for very long,” she says. “This is really around sort of satisfying our needs” of the initial launch.

Withings has partnered with the telehealth platform Heartbeat Health to give out those prescriptions. When someone takes their first EKG reading with the ScanWatch, Withings’ app batches the recording off to Heartbeat, which matches the user with a cardiologist in their state. The cardiologist then reviews the reading and can unlock the full EKG tool.

The providers at Heartbeat Health review the EKG and give the users information on what it showed — like whether it was normal or if it showed any signs of atrial fibrillation. In some cases, if the reading was unclear (like if someone was moving around too much), they might ask the user to take another EKG, Anand says.

But there aren’t really any situations where the Heartbeat Health provider wouldn’t give a user a prescription and unlock full access to the EKG. The only restriction is around age, says Jana Goldberg, the Medical Director at Heartbeat Health — the feature is only available to people over 22.

Otherwise, the review is more to make sure that the recording looks like an EKG recording should, not necessarily to make any sort of medical determination about the user, Anand says. She told The Verge that the external review reflected the company’s focus on quality and scientific credibility.

“We really wanted that added layer of quality control,” she says. “And that added layer of quality control comes with a person — that is still the gold standard.”

Still, the company has already filed with the FDA to get clearance for a version of the device that wouldn’t need users to get that that third-party review, Anand told The Verge.

Withings hopes to build out a more comprehensive relationship with Heartbeat Health that could let users talk to providers about their heart health, Anand says. Heartbeat Health also sees the relationship as a step towards their expansion into working with wearable device makers, Goldberg says: “This is probably the first step in terms of the clinical-consumer device partnerships.”