The COVID-19 pandemic has underscored the importance of wearing effective facepiece filtering respirators (FFRs) to reduce infection and disease transmission. One of the reasons causing the widespread prevalence was found to be the failure of N95-Equivalent FFRs (N95-EFs). i. e. https://www.roneverhart.com/Yamaha-PSR-SX600-Arranger-Keyboard-p26689/