The Clearblue Digital Ovulation Test detects the rise of the ovulation hormone LH (luteinizing hormone) 24 to 36 hours prior to ovulation and identifies the 2 best days to conceive in a given cycle. It's more accurate than calendar and temperature methods and gives you unmistakably clear results on a digital display. Accurately track your personal levels of 2 key fertility hormones, this test also identifies additional high fertility days that no other test can, so you have more opportunities to get pregnant. Clear results are provided, with the test indicating your fertile days. You can adjust every time you test according to your unique hormone profile. The test is accurate, over 99% accurate in detecting the LH surge in urine. It's a reliable option, using innovation based on established technology. The results are unmistakably clear, providing greater accuracy in your hands. The test is simple to use, convenient and easy to interpret.