Coarse outer foam traps large particles while fine inner foam catches the finest dustSuper Seal neoprene ring keeps out water and provides a no-grease sealBonded, two-layer foam designed for maximum protection and airflowFlexible glue is used on all seams to prevent crackingExclusive 0.65'' foamMade in the USA
https://shopping.truda.io/product/air-filter-blue
Coarse outer foam traps large particles while fine inner foam catches the finest dustSuper Seal neoprene ring keeps out water and provides a no-grease