Air Relief Slow Release Chlorine Dioxide Air Neutralizer & Freshener (2 pack) Chlorine dioxide air neutralizer - The next generation product! No water needed to activate This product continuously emits a safe amount of chlorine dioxide for 30-60 days Product will eliminate mild-mid level odors, not mask them Smoke, pet, skunk, food, H2S(rotten egg) odors are deodorized **NO P.O. BOXES - Ships via UPS Ground so a valid address is required