Ordinary wick canisters are defenseless against the ammoniating effects of air, but Scent Shots unique o-ring seal keeps air out and locks freshness in. When you're ready to hunt, just squeeze the top tabs and pull up to expose the wick and send scent streaming in the air. Push the wick back in to recharge with fresh urine. Both wick-in and wick-out positions seal the urine reservoir right preventing exposure to air and giving you a fresh scent shot for every hunt.