>>576670>20-40FUnless you're hitting over 6 mph on your bike you're not going to really need one, glasses or goggles would be more important. But if you really need one, I suggest buying any old facemask from a store and modifying it to suit your needs. I bought a cheapo $3 face mask from china, and after it stopped smelling awful and some modification, it works perfectly for everything I do in winter.
Regardless, I suggest that you find a face mask with two air vents on either side of the mouth to help air flow so you dont let it freeze to your face.
