The Xiaomi Mi Band 5 fitness tracker launched this past Thursday and is already sold out temporarily. The official Xiaomi  online store says that both the NFC and non-NFC Mi Band 5 models will be back in stock on June 30th. The latest version of Xiaomi's popular device is priced at the equivalent of $32.38 USD for the NFC model  and the equivalent of about $27 USD for the version without NFC connectivity. The Mi Band 5 is expected to launch globally next month as the Mi Smart Band 5 with both NFC and non-NFC variants.

If you live in the U.S., the Mi Band 5 can be purchased from AliExpress for a price as low as $31.99 with a coupon. This is the Chinese version of the device without NFC and is offered in Olive Green, Red, Yellow, and Black. If you order from AliExpress, keep in mind that while shipping is free to the states, your order will not arrive until July 25th.

Meanwhile, Gadgets & Wearables says that the Mi Fit app (available from the App Store for iOS devices and the Google Play Store for Android devices) has been updated to version 4.2.0. With this update, the Mi Band 5 will be able to track REM sleep. No other Mi Band model can track this phase of sleeping which is actually rapid eye movement sleep. During this part of the night, a person's eyes move rapidly and he experiences vivid dreams.

The Mi Band 5 features a 1.1-inch AMOLED display that tracks 11 different activities and monitors the user's heart rate 24 hours a day, seven days a week. The device is water resistant to 50 meters (164 feet) and the 125mAh battery will allow the fitness tracker to run for up to two weeks between charges. Charging the wearable fully will take about two hours using magnetic charging pins. The Mi Band 5 will count steps, distances, and calories burned. It will also remotely snap the shutter on your smartphone's camera. Other features include a stopwatch, alarm clock, timer, phone unlock and a way to help users find their misplaced handset. The Mi Band 5 will also remind users when they have an event to attend.

Xiaomi has always been able to sell a large number of its fitness trackers and the Mi Band 5 is off to a good start.