Clearblue & Natural Cycles Ovulation Test Refill Pack.  15 tests.  For use with Clearblue and Natural Cycles Birth Control Kit.  Contents:  1 test holder, 15 test sticks and English insert.  The digital ovulation test detects the surge in luteinizing hormone which happens 24-36 hours before ovulation, to identify your most fertile days.  Natural Cycles app subscription not included.  Exp 9/30/2026.