Designed for comfort, efficiency and style with an integrated filter socket, you get the most out of each use. - The adjustable straps secure your mask in place and ensure long-wear comfort. - Integrated metal nose clip nose for a better adjustment and to avoid fog on glasses. - Size Small & Large are 2 layers of 100% natural hypoallergenic cotton designed to enhance the breathability which allows easy long-wear. It is softer on the skin, and safe for children. Tested and certified by: Intertek - Size Medium is 3 layers of 100% natural hypoallergenic cotton and includes 2 filters. Each style was individually designed by a local Montreal artist. - Our masks include: 1 x filter PM2.5 made of 5 additional protective layers. - Filters are reusable for up to 40 Hours while wearing your mask. *Model is wearing size Medium