ALL-IN-ONE OVULATION TRACKING ✔️ Tempdrop’s wearable sensor and accompanying charting app brings the full fertility charting solution to your smartphone. Whether you are looking to increase your chances of conceiving or want to track your health, Tempdrop is tailored to you. SLEEP IN, NO PROBLEM ✔️ Basal body temperature (BBT) is a major fertility indicator that allows women to understand their cycle. The Tempdrop sensor continuously monitors while you sleep, eliminating the need to wake up at the same time each day to catch a BBT reading. No more alarm clocks and no more hassle – sleep in! EASY TO USE ✔️ Wear the Tempdrop sensor on your upper arm during sleep and then sync whenever it's convenient. With an inexpensive, replaceable battery, there is no daily charging. Available in 2 Sizes: The standard armband is 8.5 to 15.5 inches and the large armband is 12.5 to 18.5 inches. To find out your size requirement, measure around the widest section of your bicep. COMPLETE DATA FREEDOM ✔️ Option to view and track your fertility signs in Tempdrop’s accompanying app (iOS and Google Play), or input your data into other fertility apps. Use the inbuilt charting features to track multiple fertility signs and identify your cycle phases.