Features Compact folding type convenient for stockpiling and carrying. Spec Model number: 9105J-DS2 Material: Filter/PP (polypropylene), Nose pad /aluminum, Staple/iron, Head harness/polyisoprene Size: 262 x 142 x 114mm Weight: 10.1g/piece Quantity: 1 box (20 pieces) National certification passed number: No. TM636 Particle collection efficiency (average measured value): 95.0% or more (99.8%) Intake resistance (average measured value): 50Pa or less (20Pa) Exhaust resistance (average measured value): 50Pa or less (21Pa) Usage limit time: 16 hours Classification: DS2