One size fits most users, provides a balanced low-pressure positive seal Quick release shielded buckles allow fast easy removal 5 point head harness provides an even, comfortable fit with no slippage Inner mask reduces CO2 build up Anti-Fog hard coated lens simplifies maintenance and extends product life Provides optically correct wide angle viewing and is easily replaced Metal speech diaphragm enables clear, high quality communications Convenient prescription lens insert (44mm & 55mm eye sizes) with quick connection (optional-not included) Reusable respirators eliminate the need and cost of disposable N95s; proven 95% waste reduction and a 90% reduction in costs spending on NIOSH approved respirators Facepiece Material Silicone Size One Size