Sewn Adjustable Double Elastic. FFP1 Level Protection. Elastic Sewed Outside Filter Area-No Leakage, No Puncture on Filter. Aluminium Clip For Snug Fit. Low Profile Design- Fitting Wide Range Of Face Contours. Latex Free Knitted Textile Elastic- Long Life, Skin Friendly, Does not Deform in High Temperature. Unique Adjustable Beads- Gives Snug Fit. Yet Relieves Strap Pressure. One Way Exhalation Vent Valve- Provides Breathing Comfort, Promotes Easy Communication, Butterfly Vent Valve.