This digital pen style pH meter is an ideal instrument for aquarium, fishing industry, swimming pool, school laboratory, food & beverage etc. 100% brand new meter with protective plastic case and calibration screwdriver Excellent meter, very acurate and durable This Pocket Digital pH meter introduces advanced technology and imported components, greatly reducing the volume and costs and maintains the existing good quality. It used to be universal among the majority of users of all ages. Product Features : 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) Kindly note 1. This product should be part of the waterproof, some not waterproof, please be careful. 2. If no use, or not use for a long time, this product should be calibrated in the solution. First Put the electrode in the PH 6.86 solution and adjust the position with our small screwdriver. Then wash clearly and put it in the PH 4.00 solution and adjust the position with our small screwdriver. Package: 1 x Digital pH meter 1 x Calibration Adjustment screwdriver 2 x Pouches of calibration buffer solution 3 x Batteries Included in pH Meter 1 x User instruction(English) 1 x Sturdy Plastic Case