Bumpers and spacers are used as non-slip, non-marking stoppers on cabinet doors, electronics such as laptops and printers, and on the feet of small appliances. They consist of a noise damping and shock absorbing polyurethane that comes in a variety of shapes. Cylindrical and square flat top bumpers can bear heavier loads, resist wear, and prevent skidding. Hemispherical bumpers are superior at absorbing shock and sound. Hard yet flexible, they do not scratch surfaces or leave marks.