Mi Home (Mijia) Aqara Water Sensor

Midnight alarm - water leak detected! Thanx to my neighbors....

where to buy this? Does this require the hub to work with?

Hello, Jingyu Qi! On behalf of Xiaomi Global Community, as we are a wholesaler, mainly, we offer to you several options for retail purchasing of this product - you may check your product at our website and click the desired shop to proceed with retail order. Yes, it requires a hub.

Would be nice with some kind of manual..

Hello Jorgen! You can find it in the User Manuals section on our website.