suckers / suckers

We usually put opposite way for a sauce or dressing like ketchup to trickle down from the bottom , and make the bottle unstable. “Sucker” would leave the bottle inverted safely, and can be adapt for any size of containers such as ketchup, shampoo, or body emulsion.
Besides, each sucker has ”Braille” that helps the blind to distinguish the usages of containers and has different colors for children to memorize different containers.