I guess it's more for after you test positive.
The run down is this: It has 5 tests on one casette. Each test requires a subsequently higher amount of hCG. So, the first is 20 mIU, the second is 50 mIU and so on and so forth up to I think 10,000.
The point is to take them a few days apart to see how your hCG numbers are rising. Kind of an at-home beta check.
MAN I'm tempted!!! Obviously they are expensive, but what a great idea!