Maintenance free design for maximum safety and simplicity. No maintenance records are required if disposed of within one month. Replace after 28 days or when damaged, breathing resistance increase or breakthrough occurs, whichever occurs first. 2 large bonded carbon filters for low breathing resistance, low profile design for better peripheral vision. Low resistance parabolic valve to reduce heat build-up. Soft/Non-allergenic face piece material. lightweight and well balanced design. Cradle head harness. Easy to fasten neck strap. Standard: EN405:2001 . Approval: CE marked 3M 4279 Organic Vapour, Inorganic and acid gas, Ammonia and Paticulates Respirator: FFABEK1P3R D Gases/Vapours: 10xWEL or 1000ppm whichever is lower; Particulates: 20xWEL* *WEL – Workplace Exposure Limit.