WEINCELL (MRB675), Replacement (12-Package master carton) WeinCells are the only mercury-free, exact-voltage replacements for discontinued 1.35 volt mercury photo batteries. The zinc/air composition of the WeinCell delivers the same precise voltage with steady, constant output identical to that of the mercury batteries (alkaline replacements are generally 1.5 volts, with an unstable output curve; this can result in exposure errors of up to 2 stops).FEATURES: ? Compatible with any camera or meter specifying PX625/PX13, PX675 or RM400R mercury batteries. ? Voltage output more stable than alkaline replacements. ? No camera/meter adjustment or adapters required. ? Up to 10-year shelf life; WeinCells are not activated until the pull-tab is removed (removing battery and replacing tab prolongs battery life). ? Enviromentally safe.