A Virginia manufacturer of deployable smoke and fire barrier systems for openings in building cores, atria, elevator hoistways and stairwells, with products listed to UL 1784, UL 10B, UL 10C and UL 10D. Which listing a curtain carries decides what it can be used for: UL 1784 covers air leakage for smoke containment, while the UL 10 series covers fire endurance of the opening protective.