This digital pen style pH meter is an ideal instrument for aquarium, fishing industry, swimming pool, school laboratory, food & beverage etc. * Meter with protective plastic case and calibration screwdriver. Excellent meter, very accurate and durable * Measuring pH Range: 0.0 - 14.0 pH. Resolution: 0.1 Ph. Accuracy: ±0.1 pH (20°C), ±0.2 pH * Operating Temperature: 0 - 50°C (32 - 122°F). Relative Humidity:95%. Calibration: manual,1 point * Package Content: 1 x pH Meter, 1 x Screw Driver, 3 x AG 13 Button Cell Batteries (included), 1 x Instruction Manual ( English)