The 1-Gang 22-1/2 cu. in. Thermoplastic Vapor-Tight Wall Box features an offset drywall flange that is covered with a closed-cell foam gasket and additional gaskets over cable entry points. These combine to create a vapor-tight seal, ensuring that air cannot freely flow through the box. The box is made with a thermoplastic material for durability and is fire rated and UL listed to help ensure safety.