The Premium Stretch-to-Fit Mask is an upgrade of Stretch-to-Fit and still has a 3-layer mask and a pocket to replace the PM filter 2.5 as well as have two sizes that able to fit US Kids and Adults:
- Adult: 8-inch x 5.23-inch (20.32 cm x 13.34 cm). – Size M
The two side strap is elastic to ensure they are suitable for all sizes.
(*) NOTE: There is not included the PM 2.5 filter that comes along with the mask.