3M Secure Click Reusable Half Face Mask HF-800 Series is available as two versions, HF-800 and HF-800SD. The HF-800SD versions have a speaking diaphragm. Both versions are available in three sizes. 3M Secure Click HF 800 Series Half Mask Reusable Respirator helps protect against particulates and a wide variety of gases and vapours when used with approved 3M Secure Click cartridges and Filters, Greater breathability and comfort provided by the worlds first quad flow cartridge system, Push button seal check helps bolster confidence that the respirator is properly sealed to the face, Speaking diaphragm is designed to help provide easier communication while you work, Confidence that Filters and cartridges are installed properly provided by all new Secure Click connection, Low profile Half Mask design offers a wide field of view and compatibility with certain welding and grinding shields, Over-moulded design for easy assembly/disassembly, Advanced silicone material for increased comfort and greater durability EN 140:1998.