Finding the right size for a smart ring is critical. Warchody includes a size chart, and you should measure your finger circumference before ordering. A properly fitted ring means accurate sensor readings and comfortable all-day wear.

The Warchody Smart Ring Fitness Tracker 9 monitors heart rate, blood oxygen, and skin temperature through your finger 24 hours a day. It runs on Android Wear 1.0 and includes 3 GB of storage. The 1-inch screen is small but readable, and the ring requires one AA battery, which is included in the box.

Battery life is the main tradeoff here. Replacing a AA battery every few weeks is less convenient than the rechargeable batteries found in pricier rings. For the price, the core health tracking works reliably for basic daily monitoring, but don’t expect the advanced sleep or activity algorithms found in dedicated fitness wearables.