Three months after its launch, the Apple Watch Series 4 has at long last received its most hyped feature. The watchOS 5.1.2 software update was shipped Thursday and brought with it the high-end health tech that stole the stage during the iPhone keynote in September. The best part is you don’t even need a Series 4 to experience some elements of the feature.

The smartwatch’s highly anticipated electrocardiogram (ECG) heart monitor is now available. This will leverage the wearable’s redesigned biometric sensors to give Series 4 users much more accurate readings. Everyone with a Series 1 or later will also gain access to Apple’s irregular heart rhythm detector. This checks the wearer’s pulse every two hours to check for any abnormalities, which could detect signs of serious health conditions like atrial fibrillation (AFib). The only difference is that older Apple Watches will use their less accurate photoplethysmography (PPG) sensors instead of the electrodes that enable ECG in the Series 4.

apple watch series 4 ecg heart monitor
Activate the ECG feature and place your index finger on the Series 4's crown to being taking your pulse.

All you have to do is update the Watch app on your iPhone, restart your Apple Watch, then navigate to the Health app to set up the ECG and heart rhythm detector features. The app will take you through a series of prompts that will teach you how to take your first reading, which only takes 30 seconds.

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To make sure ECG is running, you’ll need to place your index finger on the watch’s crown when the ECG app is active and hold it there until the device tells you it’s done. After it’s done taking the reading, it’ll classify your pulse as AFib, sinus (which is good), or inconclusive. This data is then saved in your iPhone’s Health app where users can quickly share a PDF of their results with their doctors.

Apple makes sure to note that this is not meant to replace doctor’s diagnosis. ECG can’t detect a heart attack, blood clots, stroke, or other heart conditions like high blood pressure and arrhythmia. This feature is meant put more data in the hands of users and help them better communicate with their doctors. It’s supposed enhance your doctor’s visits, not replace them.

Now that the Series 4’s most revolutionary feature is here, the wearable is finally the consumer health powerhouse that Apple executives touted it to be in September. Better late than never.