SO, these batteries appear to be just like most others...except, these batteries actually deliver a long service life during high demand situations such as flash photography. A photographer only gets one chance at many shots, like at a wedding, and that flash has to be dependable...and why purchase the best flash unit and then put stupid little girly man batteries in it.??? These batteries were used in over 600 demanding flash deliveries during a recent wedding/reception I shot, and they were ready, on time, and lasted well into the night. When they start to drain, it is not sudden...they let your flash unit know, and any product will drain slowly....but some batteries die a quick and tragic death....and one loses that special photograph memory due to a corpse of AA's that could not perform. These batteries are reliable, dependable, a great value, and trust worthy to put in an expensive device such as a flagship photo flash unit. For sure, one can spend less, what a great value....but spend a little more and get a battery that is gonna please you. Enjoy and know, when you need a little charge in your life, these batteries wont let you down.