Hi, this is Jon, and in this clip, we'll be leveling and pluming our door. Now to check plum, you want to take your level and place it vertical on your door, and if the bubble is between the two lines that means that your door is plum. You're also going to want to put it on the inside of the door and make sure that that is plum as well. And as you can see, my hinge side of my door frame is plum. So I'm going to go ahead and put a couple screws in. And then you want to check your door again just to make sure that nothing moved on you.