I bought both versions of the Nam & Ko masks. The e2 mask is a surgical style mask with a filter pocket, behind-the-ear attachment, and a nose piece. It is reversible and a 35 percent cotton/65 percent polyester. The s1 is a contour style mask with a filter pocket, behind-the-ear attachment, and a nose piece. It is neoprene and mesh. The s1 is ideal for working out and I would go with this mask over the Under Armour mask any day for any physical exertion. The biggest drawback on either of these masks is the ear adjuster is plastic and I can see it becoming annoying with long hours of use. If I could get it off easily, I would.

4/5 Stars

Material: 35 percent cotton/65 percent polyester or neoprene/mesh

Colors: Multiple

Layers: Twp

Style: Contour and surgical

Filter Pocket: Yes

Nose Piece: Yes

Attachment Style: Behind-the-ear

Size(s): Small, Medium, Large

How to Wash: Machine or hand

Cost per Mask (not including shipping): $18.50 to 38.50

Location Made: New York

Donation: Yes