Hanna Instruments GroLine 5000 µs cm Conductivity Standard with Certificate, 230 mL Disease & Pest Control Plant Success Great White is Pesticide Dual Use Plant Success Great White is a cutting edge formula containing a highly concentrated and diverse blend of beneficial microbes these closed laboratory chillers are ideal for applications such as cooling rotary evaporators S cm conductivity standard that is prepared against a NIST traceable potassium chloride solution and supplied with a certificate of analysis Hanna conductivity solutions have the lot number and expiration date clearly marked on the label and are air tight with a tamper proof seal to ensure the quality of the solution