Anker's Soundcore Liberty 4 earbuds can monitor your heart rate

Anker's Soundcore audio brand has revealed yet more products. Among them are the Liberty 4 earbuds, which can track your heart rate. The heart rate sensor is in the right earbud, so you'll need to wear that one to use the feature. When it's measuring your blood oxygen levels, the earbud will emit a red light. Soundcore hasn't disclosed the waterproof rating, which is odd given that heart-rate tracking functions are closely linked to workouts.