Product Features/Basic Specifications Features: Screw-in type, no cap needed. Attach by screwing directly into the facepiece. Tighten the screw until it stops. Breakthrough time: 55 minutes Type: Gas cartridge Classification: L3 Weight (g): Approximately 46 Attachment method: Screw-in type Particle collection efficiency (%): 99.9 or more (DOP liquid particles) National Inspection Approval Number: TN22 Supports Dioxin countermeasures Lv2 Gas type: For organic gases Compatible masks: GM175D, GM185, GM81S, GM81SF Specifications: Absorption cartridge with dust-proof function Expiration date: February 1, 2024 This is a set of 12. Please understand that the expiration date has passed.