Matala Hakko Magnets move with the diaphragm and holds the diaphragm secure. Using worn diaphragms for extended periods of time will wear down the magnet. If you open the motor for repair and find dust or small metal particles, you may need to replace the magnet. Always inspect the magnet for wear when replacing diaphragms.
Matala replaced the HK-80L and HK-120L models with improved models HK-80LH and HK-120LH in January 2015. Please note that these pumps do not use the same magnet bar as the former air pumps.