Tink’s Peak30 Peak Heat Premium Doe Estrus is pure urine collected during their Peak Standing Estrus verses the competition estrus urine, which is collected in the pre, peak, and post estrus timeframe of a doe’s cycle. It is guaranteed to contain 30pg/ml levels of estrogen; the peak level for a doe ready to breed. Each collection goes through a scientific certification process to guarantee levels of estrogen present. Tink’s Peak30 Peak Heat Doe Estrus is the most premium estrus deer urine on the market. PURE. CERTIFIED.TESTED