--It's an inexpensive and convenient digital tool that instantly checks your total water quality.

--Display: large, easy-to-read LCD display Screen.

--TDS is great for checking the quality of tap water or knowing when to change filters.

--Aqualutio digital TDS water meters are ideal for testing applications such as hydroponics and gardening, swimming pools and spas

Description:
Name: Testing Pen

Material: ABS
Size: 155 x 29 x 10mm/6.1 x 1.14 x 0.39"
Measuring range: 0-9990 ppm, 1 ppm resolution, +/-2% reading accuracy.
Power supply: 2x1.5V (LR44 button battery) (not included)
Ideal for testing applications such as hydroponics and gardening, swimming pools and spas, aquariums and reef tanks, water ionizers, water filters, drinking water, and more.
Features:
1. Tds stands for total dissolved solids, i.e. any salts, metals or minerals in the water. At the touch of a button, the TD will tell you your total water purity and will display it on the screen in ppm (parts per million). The lower the tds content, the purer the water, pure water is 0 ppm. 
2. (The meter does not test for biological contaminants.)
3. The TDS is an excellent tool for drinking water, water filtration and purification, colloidal silver, hydroponics (testing nutrients), aquariums, ro/di systems, swimming pools and spas, commercial and industrial applications, and more. The tds is a rugged model that includes a protective carrying case. This is a globally popular handheld tds meter for industry professionals. Ts are great for commercial use. Includes a carrying case with a fixed belt clip: thanks to its advanced microprocessor technology and built-in digital thermometer, measurements are stored efficiently and accurately for easy reading, photographing and recording; 
4. TDS water meters are ideal for testing applications including Optimal drinking water, water purifiers, carbon filters, spring water, hard water, regular tap water, refrigerator water purifiers, water purifiers, filter hydraulics, reverse osmosis, reverse osmosis filters.

Packing list:
1 x Testing Pen
1 x instructions
Note:
Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. 
Manual measuring,please allow 1~3mm error,thank you.