Resize post icon box

[Mariner1]

Im wanting to resize the red box to this size 48x48.
Where and how do i do this pls im using a custom theme and vbulletin 4.2.2.Ive attached a image

[ThatGreenAlien]

Assuming I understood what you meant correctly, add this to your additional.css
.threadbit .threadstatus {
height: 48px;
width: 48px;
}