The eXact Micro 10 Advanced Photometer uses a patented method and technologies that offer faster, safer, easier, and more precise water testing. It offers the capability for ten direct reads: combined chlorine, free chlorine, total chlorine, cyanuric acid, total alkalinity, ozone, calcium, phosphate, pH and chloride/salt. Features: USEPA Compliant meter for free and total chlorine Over 10 direct read parameters: combined chlorine, free chlorine, total chlorine, cyanuric acid, total alkalinity, ozone, calcium, phosphate, pH and chloride/salt First meter to directly read combined chlorine with 0.01 precision. No math required. The ITS eXact Micro 10 Advanced Photometer Kit's proprietary optics allow for accurate testing with out cap With built-in, permanent sample cell, simply fill or dip meter into water. No color matching necessary to diagnose test results 160 test memory (saves last 20 tests per menu) Automatic countdown timer Easy-to-read LCD display Waterproof meter floats No-slip grip housing Environmentally Friendly - Uses 60% less chemicals than competitors products CE certification 2-year warranty Statistics: Measurement method: Photometric Programmed tests: Detection range Free chlorine: 0.00-11.00 ppm Combined chlorine: 0.00-11.00 ppm pH: 6.2-8.4 pH Bromine: 0.00-33.0 ppm Total alkalinity: 20-180 ppm Phosphate: 0.04-3.20 ppm Ozone: 0.00-11.00 ppm Calcium hardness: 20-990 ppm Chloride (as NaCl): 1000-9990 ppm Cyanuric acid: 5-90 ppm Transmission (30 other test parameters): 99.9-0.01% Government Compliance: European CE Mark and USEPA Compliance for free/total chlorine Resolution: Up to 0.01 ppm (mg/L) Sample required: 4 mL (0.13 oz) Operating temperature range: 0 - 50°C (32 - 122°F) Waterproof rating: exceeds IP67 Instrument dimensions: 2" x 1.4" x 6.375" Instrument weight: 5 oz (6 oz with batteries installed) Batteries NOT included; requires (4) AAA alkaline batteries NOTE: To ensure optimal performance, store your eXact kit in a cool, dry place away from excess heat (below 100°F/38°C), moisture, and oxidizers such as chlorine and bromine.