Duracell Procell PC1604 9 volt alkaline battery. order in increments of 12. Procell 9 volt packaged as follows: 12 batteries per box; 6 boxes of 12 batteries to equal 72 batteries per case. These batteries are the Procell professional industrial line of the Duracell brand alkaline batteries. They have a 7 year shelf life with the expiration month and year stamped on each battery