Camelbak Protective Mask Adapter, Type M (Canadian C4) 90522-A TYPE-M: Adapter fits Millennium, M17, M40 Series, MCU2P, M70 Series, and C4 (Canada) protective masks. M95 requires additional adapter. Use in a chemical environment requires CamelBaks Chem Bio Reservoir 4.0 (CBR 4.0). CamelBak Got Your Bak Guarantee: If we built it, we'll Bak it with our lifetime guarantee.