TS770-D Roof Louver is a dual slant-back style, self-flashing roof-mounted attic exhaust vent. Features a bird-proof construction, louvered sides are seamed to the top and the top is riveted securely to the base flashing; three louvered sides open upward to prevent shingle discoloration; weather-tight collar, seamed to the base flashing; and large nailing flange.