What is an Adjustable Ring in a Water Level Control Box ?

[pvpengg]

Hi guys,

What is an Adjustable Ring in a Water Level Control Box ?

I need to design a water level control box using a adjustable ring. But I dont have any idea about adjustable ring and how it can be used for controlling water level.

Thanks in advance !

 

[hemisboats]

Are you asking about a float system to control a given water level?