Valken Annex masks are a good quality, full face masks with large lenses that give you a great field of vision. The base mask is a tough nylon polymer with differing accessories to suit everyone's price range. 
Mi-3: Single pane ANZI rated lense with basic foam package
Mi-5: Single pane ANZI rated lense with upgraded, more comfortable foam package
Mi-7: Dual pane anti fog ANZI rated thermal lense with upgraded, more comfortable foam package