HME Seal-Tite Drop Wicks have a unique umbrella shaped cap design. This umbrella cap prevents any moisture from diluting the scent in the wick. The adjustable wick exposure is a built in feature that allows you to adjust the amount of scent that is dispersed. This scent wick hanger has a double o-ring closure to prevent scent escape before it is desired. The wick easily separates for easy dipping into scent bottles.