Its a wireless water level indicator, but I also called its 'save water & save electricity'
Its work on embedded system and the of it is 500 ft from a center point to all direction.
but u can boost up it range by added a frequency booster device.
Now its range is 41.6 floor. its indicate that, how much water is remain in your tank and reading will show on your device.
NOTE:- both device is chargeable and those receiver is connect to your device it will charge by panel those will be connect to your tank. because we can provide electricity on the water tank. It can be harmful.