Transparent design: Features a unique transparent visual design for easy observation of e-liquid levels and facilitates quick cleaning of the holder. Built-in filter: Incorporates an effective built-in filter for enhanced e-liquid treatment. Reduces stains: The filter efficiently minimizes the inhalation of smoke tar and stains, helping to reduce discoloration on teeth and fingers. Compatible design: This cigarette holder is designed to accommodate regular size cigarettes. Quality assurance: If any quality issues arise with the product, immediate replacement or refund options are available.