Scent Killer kills human scent on contact. Totally odorless, kills odors at the molecular level. Extremely effective. Totally odorless when you first put it on and keeps you odorless all day long. Spray scent killer on your clothes, it keeps the human odor from forming a gas. One whiff of human scent and your deer is gone. If you take your hunting seriously, Scent Killer is a must.