Unique Adjuster Beads- Gives Snug Fit Yet Relieves Strap Pressure. Outer Flame Retardant Layer- Protection From Welding Sparks. Activated Carbon Layer For Absorption of Nuisance Level of Odour and Vapour. Protect against nuisance level of Ammonia. Sewn Adjustable Double Elastic. Polyurethane Nose Liner For Comfortable Fit. Elastic Sewed Outside Filter Area- No Leakage, No Puncture on Filter. Aluminium Clip For Snug Fit, Cut Seal Edge- No Carbon Spillage.