Hello Welcome to our store Quality is our first consideration with best service.This digital pen style PH meter is an ideal instrument for any aquarium, the fishing industry, swimming pools, school laboratories, food & beverage, etc. And, this Digital Water Quality Tester is ideal for all basic water testing applications. This product is highly efficient and accurate due to its advanced microprocessor technology.Applied range: the production and drinking of purified water, Electroplating liquid, Boiler water, Water in fish tank, Water of swimming pools, Photograph flushing fluid, Well water, Deep phreatic water, Laboratory, Aquaculture, Food processing, etcpH Meter Features:1.Measuring pH Range: 0.0- 14.0pH2.Resolution: 0.1 pH3.Accuracy: 0.1 pH(20C), 0.2pH4.Operating Temperature: 0-50C (32-122F)5.Calibration: Manual,1 point6.Item Net Weight: Approx. 57g (after installed batteries)7.Dimensions: 152 x 29 x 20mm (5.984 x 1.142 x 0.591 inch)Digital TDS Meter Tester Features :1.This item can be used in : water purifiers and filters, food (vegetable, fruits) & drink quality monitoring, pools and spas, aquariums, hydroponics.2.Hold function : Saves measurements for convenient reading and recording3.Auto-off function : Turns off meter after 10 minutes of non-use to conserve batteries4.Dual Range : Measures form 0-999ppm, with a resolution of 1ppm. From 1,000 to 9,990ppm, the resolution is 10ppm, indicated by drinking x 10image, Factory calibratedSpecifications :1.Color :As picture shows2.Accuracy : +/-2%3.Weight : 68g4..Rang :0-9990ppm5.Item size :155mm x 28mm x 15mm6.Battery : 2 x 1.5V Button Cell battery (included)Note :Do not drop the entire TDS meter in water of dip beyond the maximum immersion level.This unit is not water-tight and is not covered under the warranty if water enters the unit.Package Includes:1 x TDS Meter Tester1 x Leather packing bag2 x 1.5V Button Cell battery1 x TDS Meter Tester User Manual(English)