This package of over 200 little rubber feet, variously sized for electronics and home appliances, should last me the rest of my life.
The variety of diameter and thickness of these assorted LRF should cover the gamut. I was finally convinced to buy them due to a missing "foot" on my space heater, but I also have a headphone amplifier and an electronic waffle iron that will soon be whole again and not tilt-y. They can also be used for drawer bumpers if needed.
Rubber Feet, 232 Pieces Clear Adhesive Bumper Pads via Amazon
