Kirinstores (TM) Digital LCD Ph Meter Tester Mini Pocket Auto Pen for Aquarium Pool Water with Retail Box Operating Temperature: 0 - 50C (32 - 122F) Measuring pH Range: 0.0 - 14.0 pH Resolution: 0.1 pH ;Calibration: manual,1 point Accuracy: 0.1 pH (20C), 0.2 pH Weight: 65g ;Size: 15 x 3 x 1.5 cm