1 pack for 10 KN95 masks. 
YECO’s non-medical KN95 mask conforms to the GB2626 standard, which the CDC recommends manufacturers satisfy for non-medical N95 style masks produce in other countries, as the standard mentioned in the chart. The masks have been independently tested by an International Testing Group to certify that they meet the GB2626-2020 standard.
Our masks are guaranteed to provide 95% filtration rate of 0.3 micron and larger particles, as certified by the independent third party testing organization.
 
The most important aspect of our masks is that they use real meltblown non-woven fabric! Meltblown non-woven fabric is a primary material used in the manufacturing of medical and surgical masks. This middle layer is usually created from polypropylene (PP) melt-blown non-woven fabric and is treated to be an electret. The electret treatment adds electrostatic properties to the filter layer allowing for electrostatic adsorption which helps to trap aerosolized particles via electrostatic attraction.
The masks are made from top quality meltblown fabric sourced from the raw material feedstock of one of the largest and most respected petrochemical companies in the world.
 
As shown in the pics, when lighting it up, real meltbown non-woven fabric will melt with obsolutely NO FLAME; it won’t burn and it won't generate soot or ashes. 
When torn up, quality meltbown fabric will be held together by the fabric’s static charge because of its electret treatment.  
 
Many KN95 mask sellers are selling 4 layer KN95 masks. YECO’s KN95 masks have 5 layers, with 2 layers of meltblown non-woven fabric, which means better quality.