North’s Pancake filters really stack up with a low profile design and low resistance. These P100 filters are specifically designed to fit under welding helmets and faceshields, including the latest generation of narrow shell helmets. They are flexible enough to fit in even the tightest spots, yet still firm enough to easily perform negative pressure user seal checks. The Stack Pack contains an optional adapter that allows you to use North’s Pancake as a pre-filter on North cartridges. Perfect for extremely dusty environments where you need P100 protection. Change the Pancake filters as frequently as needed and retain the chemical cartridges until cartridge change-out. The Stack Pack from North contains one pair of adapters and 5 pair of 75FFP100 filters.