4x3 Decal. It includes a removable adhesive, and is rated by the manufacturer for up to 3 years durability once printed, and removable up to 1 year (for the easiest removability). Its also resistant to most mild acids, alkalies, and salt solutions.
The vinyl material is NOT guaranteed to be removable from:
-Surfaces with poor paint-to-substrate adhesion
-Existing graphics that must remain intact
-Aged paint or metal that may have surface oxidation or chalking
-Outdoor, horizontal surfaces