We carry self storage door numbers in two layouts, horizontal (side by side) or vertical (up and down). The picture below shows the difference. A horizontal layout is the most common for mini warehouse doors and buildings, however, for door posts or door frames, a vertical layout is needed. We carry both styles in all sizes of numbers and letters. Horizontal letters are available in both non transfer taped and transfer taped sheets. Vertical letters are available in transfer taped pre-spaced letters only. Transfer taped letters are pre-spaced and pre-masked to hold them together during installation. Simply apply, and peel off the transfer tape layer.