The KEMP USA 10-523 Ambu Adult Child Combo CPR Masks with O2 Inlet, Headstrap, Gloves, and Wipes in Soft Case Pouch features an optional patented one-way valve with filter. This mask prevents mouth-to-mouth contact with the victim's face. Its transparent dome allows the rescuer to check the victim's mouth for lip color and secretions. The mask is ready to use with no need to assemble valve and filter, which saves valuable time in emergencies. This kit also comes with a child adapter, allowing for administering safe and effective CPR to small faces.