This gasmask is size medium, as evidenced by the model number (the vast majority ofpeople take a medium size gas mask). Made in the USA! This model is officially NIOSH rated for protectionfrom chemical, biological, radiological, and nuclear (CBRN) hazards. Has butylrubber seals and 40MM NATO threads for accepting cartridges/filters/canisters. Comes with two (2) new factory-sealed Scott Safetymodel number 045135 NIOSH-rated P-100 CBRN filter cartridges/canisters. Made inthe UK, date of manufacture 05/23/2020, expiration date 05/2028. Threaded 40MMNATO, so compatible for use with the paired gas mask. The seals have NEVER beenbroken or tampered with on the filter cartridge factory packaging. Everything always stored boxed in a closet, away fromany harmful sunlight/UV/heat exposure. Bought for preparedness purposes only, so never used any of this.