continuous update between two ui elements

Hi,

I know I've come across an object (perhaps 3rd party external) recently which allowed for continuous update between multiple ui elements. The example I believe was a slider and a number box, where if the slider's value was changed, then number box updated to the new value of the slider, and also if the number box's value was changed, the slider updated to it. I've tried to retrace my steps, but cannot find it. If anyone knows what I'm talking about or something similar, please let me know.

Thanks!