Apple Watch Series 4 is gaining the promised new ECG app later today, and CBS This Morning has aired a new segment with Apple’s Jeff Williams and Dr. Sumbul Desai to discuss the new electrocardiogram feature.

Apple Watch Series 4 will be able to take an electrocardiogram using electrodes on the Digital Crown and heart rate sensor on the back for customers in the United States starting with watchOS 5.1.2. We expect the software update to be released about 1 p.m. ET today.

Apple COO Jeff Williams and vice president of health Dr. Sumbul Desai both appeared on CBS This Morning today to promote the new heart health features including new heart rate alerts coming to Apple Watch Series 1 and later.

In the clip, CBS references analyst estimates that put total watch sales around 50 million units to date, and Jeff Williams says that Apple has sold tens of millions of watches by explaining that Apple has heart rate monitors on that ballpark estimate of customers.

Here’s the segment that aired this morning:

CNBC and CNET each have hands-on videos as well:

Stay tuned for more ECG app coverage later today, and read our Apple Watch Series 4 review for more on the latest version.