I have had essentially zero luck with any "commercial" so called estrus scents. I don't buy any of these. I collect all the deer urine that I can from every deer that I kill. I make no effort to seperate doe from buck. I keep all excess frozen. Make mock scrapes with a mixture of this urine, and have used a "drip" bottle. I also utilize oiled up tarsal glands that I have removed from bucks to rub nearby overhanging limbs and saplings. Any tarsals I am not using I also keep frozen also. This has worked pretty good for me over these past 35 or so years. I have had tons of does urinate in these moc scrapes, bunches of 2-3 year old lucking bucks and occasionally some really nice bucks visit. Having fresh, oiled up tarsals to scent up the area around the moc scrape seems to really be a key to getting the larger bucks to come take a look.