HXQ Digital TDS meter Hardness testing equipment 0-9990 ppm Measurement Range ， 1 ppm Resolution， +/- 2% Readout Accuracy<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>The mini design is as big as palm</li><li>Ideal for water purification， wastewater regulation， aquaculture and hydroponics， colloidal silver</li><li>Recommended for freshwater aquarium， shrimp， crab farming， gardening and water， swimming pool and Spa</li><li>Hold Button: Holds measurement value when meter is removed from water for convenient reading and recording</li><li>Auto-off function: the meter shuts off automatically after 10 minutes of non-use to conserve batteries</li></ul></div><img src="http://ecx.images-amazon.com/images/I/410mcYi8SYL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31RuqVV4qPL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41oqbP1DtML.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41ZOZe5r8qL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41UujI1HFDL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41AcFok8IlL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41fV5nf8qrL.jpg" noproxy>