ECG on a Smartwatch: What It Can Detect and What It Can’t
A smartwatch ECG can flag signs of atrial fibrillation, but it cannot detect heart attacks or most other heart conditions. Here is what the readings mean.
Features Explained
How Optical Heart Rate Sensors Work on Your Wrist
The green lights on the back of your watch read your pulse by measuring how blood absorbs light. Here is how optical heart rate works and how to get better readings.
IP68 vs 10 ATM: What Wearable Water and Dust Ratings Really Mean
IP68 covers dust and brief submersion, while 10 ATM covers water pressure for swimming and water sports. Here is how to read both ratings on a wearable spec sheet.
What Does 5 ATM Mean? Smartwatch Water Resistance Ratings Explained
5 ATM means a watch handles pressure equal to 50 meters of still water, enough for swimming laps but not diving. Here is what each water rating allows in real life.
Dual-band GPS on Smartwatches Explained: Why It Tracks Your Route More Accurately
Dual-band GPS listens to two satellite frequencies, L1 and L5, so your watch can spot and reject bounced signals. Here is why that fixes zigzag routes near tall buildings and trees.