Hanna Checker®HC Alkalinity colorimeter (dKH)
 Standard test kits have limited accuracy since they rely upon the human eye to match colors. The Hanna Checker HI-772 eliminates the hassle of matching to a color chart by providing a direct saltwater alkalinity result in dKH units.
The HI772 Checker®HC (Handheld Colorimeter) provides a simple, accurate, and cost-effective way to measure alkalinity in degrees of carbonate hardness, commonly abbreviated as dKH. 
Critical to marine environments, alkalinity not only provides the carbonate ion required for calcium carbonate skeletal regeneration of coral reefs, but it also acts as a pH buffer against large changes in acidity. Designed as a more accurate alternative to chemical test kits, the HI772 provides quick, accurate results in a few easy steps.
Sepcifications:
Range : 0.00 to 20.0 dKH
Resolution : 0.01 dKH
Accuracy @ 25°C : ± 0.3 dKH ±5/ of reading
Light Source : LED @ 610nm
Light Detector : silicon photocell
Battery Type : (1) 1.5V AAA
Auto-off : after 10 minutes of non-use
Environment : 0 to 50°C ; RH max 95% non-condensing
Dimensions : 86.0 x 61.0 x 37.5 mm
Weight : 64 g
Calibration Set : HI772-11 Not included
Warranty : 1 year
What's inculded
1x HI772 Checker®HC 
2x sample cuvettes with caps
1x HI772-26 reagent (25 tests)
1x syringe with tip
1x batteries
1x instructions, and quick start guide.