Additional Details ------------------------------ Product description: 3M(TM) Speedglas(TM) Adflo Prefilter 15-0099-99X12 Package of 12 genuine Speedglas(TM) Adflo replacement prefilter. Prefilter helps catch dust and other large particulates and extends the life of the main Adflo HEPA filter. Free standard ground shipping within contiguous U.S.