1080p clip stays distorted on 4k sequence

[AJLeibman]

Hello all, 
I'm editing a short video about an open-water swimmer who is blind. Everything was shot in 4k except one clip was shot in 1080p, which stays distorted on my 4k sequence or when I make a 1080p sequence. It is set to "set to frame" size and still is distorted in Premiere. However, it plays just fine in Quicktime, so I know the clip isn't corrupt. I gotta be overlooking something that's probably obvious . I've attached screen grabs from QT, distorted clip, meta data and media prefs. Thanks very much for any help! 
-AL 

[AJLeibman]

I've attached on more screen grab of all the panels in the hope that could be helpful for any feedback. 

[Peru Bob]

What does it look like if you uncheck "Set to frame size" and manually resize it?

[AJLeibman]

Peru, I tried that, but the clip stays distorted. Thanks. -AL

[Ann Bens]

You do not change the sequence settings you modify the clip.

[AJLeibman]

Yes, I understand. But how exactly do I do that? Thanks. -AL

[Ann Bens · Accepted solution]

Right click on clip

[AJLeibman]

Thanks for the screen grabs! I'll try that as soon as I get home. 

[AJLeibman]

Ann, that worked beautifully! Thank you very much for taking the time to help out. My clip plays how plays perfectly on the timeline. Much appreciated. -AL

[Ann Bens · Accepted solution]

Your clip has an odd pixel aspect ratio as in 3.5556

It should read 1.0. (modify clip)

[AJLeibman]

Ann, it sounds like that might be corrrect. I know how to change the sequence settings, but how would I change the clip's aspect ration? Thanks. -AL