These masks are made in two robust and durable layers.  
The outer layer is a heavy duty waterproof PVC coated Otterex material and the inner layer is made from light weight, soft rip stop military uniform material.  This fits extremely well and tucks nicely under the chin.
In addition, there is a malleable nose piece for better fit as well as two additional metal strips to help keep the nose and mouth open for better breathability.  
The mask is washable and can be put in the dryer under low heat.  
The masks are available in 21 colors