●HIGH QUALITY PART: TOMOON April.aire 35 water panel for humidifier is a top-of-the-line replacement part designed specifically for April.aire 300 series humidifier.It utilizes multiple layers of thickened paper to increase the filtration area, thus enhancing the filtration effect. And we add 2 layers of aluminum alloy to greatly improve the april.aire 300 replacement filter bending resistance! ●PERFECT FIT: The actual size of the filter is 10" x 13" x 1.75", making it a perfect replacement for the April.aire 400, 400A, and 400M humidifiers. Replacing the Apr.ilaire 400 series humidifier filter every year allows the humidifier to last longer. ●INCREASE AIR HUMIDITY: By regularly replacing the april.aire 600 humidifier filter water panel, you can ensure that the April.aire humidifier consistently and effectively maintains the air humidity level in your entire living room at 40%-60%, helping to prevent dry skin, static electricity, dust buildup, and respiratory discomfort. ●EASY INSTALLATION: Replacing the TOMOON A-prilaire 400 replacement filter is a straightforward task that can be completed without any professional assistance. Simply remove the old Aprilaire 45 water panel and slide in the new one, saving your precious time. ●COST-EFFECTIVE SOLUTION: By choosing TOMOON, you will receive 4-pack of April.aire 45 replacement filters, providing an affordable way to keep your Aprilaire humidifier performing optimally. Our perfect after-sales policy also ensures that you have an excellent shopping experience.