Includes 4oz each of 4.00 and 7.00 buffers. We package these solutions from bulk quantities to get you the best pricing. For testing, pour buffers into a small glass. You do not want to stick the probe of the pH meter into the buffer jars directly because you will eventually sacrifice the accuracy of your buffers.,Expires after 6 months if unopened. Expires after 3 months if opened.,Click here for a PDF of the MoreManual on proper pH Meter care.