How to hide these "cube"

[wy.klight]

Hi, I am wondering is there a way to hide or shrink the highlighted cube? It is created by inserting keyframe to the helper. 

It is in my way when I am trying to create animation. 


*I apologies for calling it "cube" as I am not aware of the technical tarm for it.  

 

[L30n2855]

its called "viewport selection show selection bracket toggle" in the hotkey editor. hotkey is by default shift+j i think ...