magx magnetic vent cover 8"x17" (2 sheets), flaxible anisotropic magnet of ultra thick 1.5 mm, for air registers or floor air vents, rv, home hvac, ac, home must buy magx magx magnetic vent cover 8"x17" (2 sheets), flexible anisotropic magnet of ultra thick 1.5 mm, for air registers or floor air vents, rv, home hvac, ac, home must buy