This 7-parameter test strip kit provides quick, reliable water testing for hot tubs and spas. With 150 strips per bottle, you have plenty of testing power to keep water balanced throughout the season. Dip for 1 second, remove, hold horizontally for 15 seconds, and compare against the color chart on the bottle to read bromine, total alkalinity, pH, free chlorine, total hardness, cyanuric acid, and total chlorine. Read in natural daylight for best accuracy, and store in a cool, dry place. Expiration is 3 years from manufacture, and once opened you should use the strips within 90 days. Compact bottle measures 3.94 x 1.97 x 4.72 in, and packaging is 4.4 x 1.9 x 1.8 in, making storage simple and convenient.