yolink smart home starter kit: amazon's choice water sensor 4-pack & hub kit - our best-selling original water leak sensor (qty. 4) and hub kit. sensor compatible with alexa and ifttt yolink product requirements:<br> the smartphone or tablet able to run ios 9 or higher; android 4.4 or higher.<br> <br> specifications:<br> yolink hub<br> input: 5v dc<br> maximum current: 1a<br> working temperature: -20°c~50°c (-4°f~104°f) <br> humidity: 0~90% non-condensing<br> <br> yolink water leak sensor<br> product model: ys7903-uc<br> voltage: 3v dc (2* aaa battery)<br> working temperature: 0°c~50°c (32°f~122°f) <br> working humidity: ≤100%rh (non-condensing) <br> <br> package content: <br> 1 x yolink hub<br> 4 x yolink smart water leak sensor