That is the total number of tests, but when you test for ammonia, nitrite, nitrate, and pH, that is 4 tests. (and you will probalby only use one of the two pH bottles, one is hihger range, one is lower)
I have had this kit for over a year and love it, though i'm not sure if it expires or not. I've heard mixed things, like 3 months for nitrate tests, and a year for everything else. I've had mine for about a little less than a year. I usually just replace the whole thing when the ammonia test runs out.