<p>Memory<br><br>•⁠ ⁠Saves 7 days of detailed motion data, minute by minute<br><br>•⁠ ⁠Saves daily totals for the last 30 days<br><br>•⁠ ⁠Stores heart rate data at 2-second intervals<br><br>-----<br><br>Battery and power<br><br>•⁠ ⁠Battery life of up to 7 days. We recommend charging your tracker every few days to ensure you are always tracking.<br><br>•⁠ ⁠Battery type: Lithium-polymer<br><br>•⁠ ⁠Charge time (0-100%): 90 min<br><br>•⁠ ⁠Quick Charging: 1 day of battery life in 5 min<br><br>•⁠ ⁠Radio transceiver: Bluetooth 5.0<br><br>-----<br><br>Materials<br><br>•⁠ ⁠The Fitbit Air housing is made of recycled polycarbonate and PBT plastics.The band is made of textile and has a stainless steel buckle.<br><br>-----<br><br>Sensors &amp; components<br><br>•⁠ ⁠Optical heart rate monitor<br><br>•⁠ ⁠3-axis accelerometer + gyroscope<br><br>•⁠ ⁠Red and infrared sensors for oxygen saturation (SpO2) monitoring<br><br>•⁠ ⁠Device temperature sensor (skin temperature variation available in the Google Health app)<br><br>•⁠ ⁠Vibration motor<br><br>-----<br><br>Band size<br><br>Textile and polyurethane:<br><br>•⁠ ⁠One size<br><br>•⁠ ⁠Wrist size: 130-210 mm around<br><br>Silicone:<br><br>•⁠ ⁠Small wrist size: 130-175 mm around<br><br>•⁠ ⁠Large wrist size: 165-210 mm around<br><br>-----<br><br>Water resistance<br><br>•⁠ ⁠Water resistant up to 50 metres. After getting the band wet, we recommend drying the band because, as with any wearable device, it’s best for your skin if the band is clean and dry.<br><br>-----<br><br>Heart rate<br><br>•⁠ ⁠Like all heart rate tracking technologies, accuracy is affected by physiology, location of device and different movements.<br><br>-----<br><br>Dimensions (without band)<br><br>•⁠ ⁠Length: 1.4 in (34.9 mm)<br><br>•⁠ ⁠Width: 0.7 in (17 mm)<br><br>•⁠ ⁠Height: 0.3 in (8.3 mm)<br><br>-----<br><br>Weight<br><br>•⁠ ⁠0.01 lb (5.2 g) without band<br><br>•⁠ ⁠0.03 lb (12 g) with band</p> <p>• 1 Year Manufacturer Warranty.<br><br>• While Stock Lasts.</p> <p>Store in a cool dry place.</p> <p>China</p>