Red Adjusting Box?

Hi, I have this red box which appeared in the place where I view the video...It seems to be used to adjust the video up or down.

I have attached a screen shot which you can see this little red box on the right

Excuse my crap terminology but i have no idea about the terms yet.

Welcome Russell to fcp.co

click into the Preview Window
hit shift-Z
=> 'fits' the preview to the windows size …

not meant offensive, but considering your other post - may I suggest a from-the-ground course How To Use FCPX?
There are excellent commercial ones (rippletraining), some good ones for free (Lynda), a few books (Tom Wolsky), finally the built-in Manual of FCPX, …

sorry for appealing grumpy, but a forum never replaces a fundamental learning of the basics …

Karsten Schlüter wrote: not meant offensive, but considering your other post - may I suggest a from-the-ground course How To Use FCPX?
There are excellent commercial ones (rippletraining), some good ones for free (Lynda), a few books (Tom Wolsky), finally the built-in Manual of FCPX, …

I am on lynda now. The course a m 49% through is 8 or 9 hours long and I've watch that half twice and taken notes, followed by hours upon hours of hands on practice. I'm an audio (logic pro x) guy not video and I can't believe some of the things people don't know in audio but it's like learning an instrument, it takes time, some slower than other, so it's literally impossible to to just come in an go hocus pocus magic dust poooof: I know everything now :woohoo: