Built-in Smart chip offers advanced functions and features to a stick style pH meter not found anywhere else RENEW feature that tells you when it's time to replace your pH electrode CAL feature that tells you when it's time to recalibrate your meter Flat Surface pH electrode that is completely waterproof and rugged enough to withstand harsh environments Analog bargraph originates at neutral point (pH 7.00) to conveniently view trends in acidity or alkalinity Temperature measurements with Atomatic Temperature Compensation 1, 2 or 3 point calibration automatically recognizes buffer solutions. Order pH buffers separately