Yes, the Huawei Watch GT 4 (41 mm, stainless steel) can recognise sleep and different sleep phases, including light sleep. The watch is equipped with the "HUAWEI TruSleep™" function, which monitors sleep behaviour and also offers the option of waking the user in an optimal sleep phase. This function makes it possible to wake the user in a light sleep phase to make them feel fresher and more rested.