MSA 7-204-1 M4C3 Ultra-Twin Full Face Respirator Gas Mask Medium. Good working condition Signs of light previous use. Includes: (2) Sealed GMC-P100 815188 Cartridges. MSA Ultra-Twin Respirator, a full-facepiece respirator with specifications including a polycarbonate lens, in turned lip for a good seal, a large chin cup for proper fit, and a five-point headstrap with roller buckles. It also features a nosecup to reduce lens fogging and a speaking diaphragm for clear, short-range communication. This respirator is NIOSH-approved and compatible with various threaded Comfo cartridges for protection against dust, particulates, and toxic atmospheres (non-IDLH). Key specifications and features. Facepiece: Full-facepiece design made of Hycar or silicone. Lens: Large, wide, scratch-resistant, and chemical-resistant polycarbonate lens. Sealing: Features an in turned lip for a comfortable seal and a large chin cup for easy positioning. Headstrap: Five-point suspension headstraps with roller buckles to hold the facepiece securely and minimize hair entanglement. Communication: Includes a speaking diaphragm to provide clear short-range communications. Fogging prevention: Incorporates a nosecup to help eliminate lens fogging. Compatibility: Uses threaded Comfo cartridges for protection and is approved by NIOSH. Applications: Suitable for general industry, welding, riot control, CBRN, and utility applications.