①. ATC FUNCTION: Multi function multi parameter test pen OW‑100 can perform salinity, TDS, EC and temperature measurement, can display temperature reading on LCD at the same time. With automatic temperature compensation (ATC). ②. LCD DISPLAY: Large screen easy to read data display, two line subtitle LCD with backlight. Ingenious design structure is scientific and reasonable. ③. 4 IN 1 MULTI FUNCTION: Fast, efficient, accurate, portable test pen that integrates salinity, TDS, EC and temperature measurement to fully meet your measurement needs. ④. WIDE APPLICATION: Widely used in aquariums, aquaculture, laboratories, chemical reactions, food brewing, water purification, swimming pools, institutions, etc. ⑤. ENVIRONMENTALLY FRIENDLY ABS: Water quality meter is made of ABS material, possess impact resistance, scratch resistance, environmentally friendly. ⑥. Item Type: Water Quality Meter. ⑦. Model: S-100. ⑧. Battery: 3 x LR44 (not included). ⑨. Material: ABS. ⑩. Uses: Widely used in aquariums, aquaculture, laboratories, chemical reactions, food brewing, water purification, swimming pools, institutions, etc. ⑪. Basic Parameters: Measuring Range: Salinity: 0.00-25.00%/10.1-200ppt; TDS: 0-10000ppm/10.1-200ppt; EC: 1-10000μs/cm; 10.01-19.99ms; 20.1-400ms/cm; Temperature: 0.1~60℃. ⑫. 1 x Water Quality Meter. ⑬. 1 x User Manual.