Nasal irrigation requires a 500ml capacity. 500ml is strongly recommended. I myself use 500ml. As a user, I feel that 300ml might not be enough to wash everything out, leaving a sense of incompleteness, but with 500ml, I feel that the cleaning reaches every corner of the nasal cavity. Don't lose to Corona! Virus countermeasures House dust Yellow sand PM2.5 Pollen countermeasures! Effective for rhinitis and sinusitis! Care for dust, cleaning of the nasal cavity! Also effective for preventing colds! In addition, nasal irrigation is attracting attention from various organizations for its various health benefits. Nasal irrigation is possible with a cup, but with this device, you can do nasal irrigation truly effortlessly and easily. It's definitely easier (^^) How to use Make physiological saline by mixing about 4.5g of salt with 500ml of lukewarm water or water. Unlike regular water, using physiological saline, which is close to body fluids, will prevent the stinging sensation in your nose. I myself use it every morning. We recommend daily use for your health. Body care Health Relaxation Rhinitis Hay fever House dust Dust Allergies Yoga Corona Yellow sand Sinusitis Omicron 8