KoiMedic Salinity Tester is specially designed to measure the delicate salt concentration in the pond. The tester can display measurement in percentage (%) or parts per thousand (ppt).The tester is easy to use and accurate. It is the best companion for Koi or fish requiring the tonic of salt to improve health.Advanced Features: Display reading in % or ppt. One touch calibration. TECHINICAL DATA Model: KoiMedic Units of measurement % ppt Range: 0.00 to 1.00% 0.0 to 10.0 ppt Resolution: 0.01% 0.1 ppt Accuracy: ± 0.03% ± 0.3 ppt Battery Type: 4 x 1.5V button cell (Alkaline A76 or equivalent) Battery Life: Approx. 150 hours Automatic Temperature Compensation: 0 to 50°C or 32 to 122°F Packaging Dimension Size (LxWxH): 185mm x 65mm x 25mm Packaging Weight: Approx. 135gm Product Dimension Size (LxWxH): 170mm x 32mm x 15mm Product Weight: Approx. 70gm