How accurate is the heart rate monitor on the Apple Watch? As accurate as a dedicated wrist-worn heart rate monitor, according to one man who recently compared data between the two devices. That’s pretty amazing, and it’s good news for folks who rely on that sort of data during a workout.

SonoPlot engineer Brad Larson recently posted a graph on Twitter that shows a comparison between the heart rate data from the Mio Alpha, which grabs information every 3 seconds, and the Apple Watch, which pulled in data every 5 seconds during a run. “The readings are nearly identical,” Larson said, referring to the chart you see above. “Impressed.”

A quick Google search shows that the Mio Alpha costs anywhere between $149 and $169; considering the Apple Watch is just as accurate but can do a lot more, we’re just as impressed as Larson is.