Aquarium Systems SeaTest NO2 Nitrite (100 Tests) is a nitrites test for freshwater and seawater. Ideal value recommended: 0.0mg/l. For approximately 100 tests. Graduated 7-colour colour scale (0; 0.05; 0.25; 0.5; 0.75; 1; >1mg/l). For a result accurate down to 0.01 mgl, use the Aquarium Systems NO2 test in combination with SeaTestControl. This device is especially and uniquely calibrated for Aquarium Systems tests. Caution, observe the precautions for use.