What is the specification of non-woven mask?

What is the specification of non-woven mask? Masks are generally made of 15g, 20g, 25g and 30g PP non-woven fabrics, and the conventional gram weight is 15g, 20g and 25g, there are also 20g 20g 25g. Generally speaking, flat masks are divided into cotton masks, non-woven masks, polymer masks, activated carbon powder filter masks and activated carbon fiber pad masks. Dimensions: 18 × 9 (Adult), 15 × 9 (Children). Specifications of non-woven mask: a) Dimensions of the center part after Rectangular mask is unfolded: length not less than, width not less; B) Size of compact arched mask: Transverse diameter not less than, longitudinal diameter not less. C) The nose clip is made of flexible plastic material with a length of not less than 8. 5 cm. D)Three-layer non-woven mask size 17. 5mmx19. 5mm