New "cloth junction" means that maintenance is no longer a problem! No more reading errors due to contamination and clogging of the junction. By simply pulling out 2mm of "cloth", you'll have a new and clean junction! Replaceable electrode. Measurement range of 0.0 to 14.0 with an accuracy of +/- 0.2. Battery life lasts up to 800 hours of continuous use. The ph electrode is replaceable and requires either one point or two point calibrator solutions. (use with pH 4.0 and/or 7.0 calibrated solutions) For more information on Hanna™ products please visit www.Hanna™inst.com.