General Hydroponics PH 7 Calibration Solution for Gardening， 1-Quart</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>General Hydroponics uses the highest quality electronic meter reference solutions</li><li>Growers can use our reference solutions widely among many popular brands of meters using the NaCl scale</li><li>General Hydroponics technicians check each batch to ensure that our solutions are exactly calibrated each time they are used</li></ul></div></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br><img src='http://ecx.images-amazon.com/images/I/411AQj5%2BVuL.jpg' noproxy></br><img src='http://ecx.images-amazon.com/images/I/41M%2B2FomNqL.jpg' noproxy></br><img src='http://ecx.images-amazon.com/images/I/31RzmqLrGTL.jpg' noproxy></br>