Pocket Pen Water PH Meter Digital Tester PH-009 IA 0.0-14.0pH for Aquarium Pool Water Laboratory This digital pen style pH meter is an ideal instrument for aquarium, fishing industry, swimming pool, school laboratory, food & beverage etc. Excellent meter, very accurate and durable Operating Temperature: 0 - 50C (32 - 122F) Accuracy: 0.1 pH (20C), 0.2 pH Size: 15 x 3 x 1.5 cm