"The Climber" can scale walls, ceilings or rounded surfaces and can overcome rough surfaces, contours and obstacles as big as 1 inch off the surface. Since even a smooth wall may contain obstacles, bolts, sills, or dirt, the robot needed to have some ability to deal with rough surfaces. ICM developed a thick foam rubber pad that forms a "rolling pressure seal" for the vacuum and acts as tank treads. The foam is able to handle 3/4-in (20 mm) bumps, which gives it the ability to climb brick walls, steel plates, and aircraft exteriors.