purchased duracell button batteries, 3pk,type 303/357. installed 2 of them in an electrical tester, they were dead. immediately went back into Kmart to tell them the problem,and ask for a replacement. was informed that since i opened the pkg, they would not refund or exchange them.so I guess you are stuck with buying dead batteries from this Kmart, and losing your monies. the item cost 9.99.