Smart Scale with Connected Features. Wi-Fi® connected. Measures weight, body mass index, body fat, muscle mass and more. Auto detects up to 16 users. Up to 9 months of battery life. Whether you’re an athlete in training or just trying to maintain a healthy weight, Garmin Index smart scale provides the metrics you need to track progress and see results. It measures weight (lbs, kg, st), body mass index (BMI), body fat, water percentage, bone mass and skeletal muscle mass.