Procell Battery, Non Rechargeable Dry Cell Alkaline, 9V, 12 PK ORS NASCO Cartridges come with a new Cartridges come with a new inhalation valve for less maintenance and fewer parts to inventory Conforms to the contours of your face without pressure points Extra wide flange seals easily and stays sealed even when talking Low profile provides a wider field of vision than any other respirator Soft yet durable facepiece designed for comfort flexible gaskets directly on the flange Recommended for sealing all types of flanges 9V batteries are guaranteed for 5 years in storage Recommended for scheduled battery replacement programs Economically packaged in bulk and individually date coded for effective inventory management C and D batteries are guaranteed for 7 years in storage