The Whirlpool WPW10077881 Rinse Aid Dispenser Cap seals the rinse aid reservoir to prevent leaks and retain liquid between refills. This threaded replacement cap fits onto the dispenser opening inside compatible dishwasher doors and can be removed for convenient refilling. It keeps rinse aid contained until the dispenser releases it during the rinse cycle, supporting consistent dispensing and improved drying results. A loose, cracked, or missing cap may cause leakage or liquid loss. Replacing a damaged cap restores a secure seal and proper rinse aid containment. Designed for compatible Whirlpool dishwashers, this part supports reliable dispenser function and routine maintenance.