So there are two ways to install our wall padding, with nails or with z-clips. Nail margin essentially just means that you have to nail the wall pads to the wall. This is typically done with a 1" nail margins on top and bottom, hence the name 'nail margin,' and would be considered a permanent installation. The other way to is with z-clips. So there are two parts to a zip clip, one that attaches to the wall and one that attaches to the pad. When you hook them together, they look like a 'Z,' hence the name z-clip. This installation is a semi-permanent installation and allows you to install and remove pads as need be, easily. The z-clip option is more expensive, but the ease of installation and the flexibility it gives you could be worth the money.