Never run out of your favorite Yankee Candle fragrance when you're on the road & at home. Smart Scent Vent Clips have a clear window so you can easily see when a replacement is due. The odor-neutralizing unit fastens securely to any vehicle's dash vents &your home's AC vents. The fragrance is released as air flows from the vents. Smart Scent Vent Clips work optimally in temperatures of 70F or above flowing from the vent. You may adjust the strength of the fragrance using the slider on the back of the clip There's cool summer refreshment in this tropical blend of pineapple, grapefruit and mango.