Two models with varying resolution & accuracy; the ST10 and ST20 offer a convenient way to measure pH, or therelative acidity or alkalinity of a sample at a given temperature.Model ST10:Range: 0.00 €“ 14.00 Resolution: 0.1 pHAccuracy: 0.1 pHDisplay: SingleAuto Shutdown: 6 Mins of Non-Use Batteries: 4 AG13 1.5V Size/Weight: 185 × 45 × 38mm, 110g