Panasonic U, U3 and U6 Micro Filtration Bag, 12 Bags Treated with Ultra-Fresh for Models MC-115P, MC-V145MS, MC-115PT and MC-V145MST PANASONIC Series Uprights Micro Filtration vacuum bags also capture 99% of particles 5 microns in size, including household fibers and other microscopic allergens The Ultra-Fresh finish on these bags protect against odor and stain-causing microbial growth; This helps keep your bag cleaner and fresher Ultra-Fresh treated bags are guaranteed from defects