AliExpress sells good smartwatches from the Xiaomi ecosystem.
What is the model
The model is called Haylou RS4. It boasts an AMOLED display with a diagonal of 1.78". The screen is covered with glass with small curves on the sides and has HD resolution. The watch is not afraid of water (IP68 protection) and it can track sleep, pulse, blood oxygen levels (SpO2), and also 12 sports modes.
As for the operating time, the gadget can live from one charge to 10 days. Naturally, autonomy will depend on usage scenarios. The watch weighs 48.6 grams without a strap.
You can buy Haylou RS4 on AliExpress for $44.