Large molded plastic vent with 40° swivel. Thumb operated closure controls degree of opening. Mounts in 2- 1/2" dia. hole. Large orifice (1-3/4") provides maximum cooling. Mounting in floor of aircraft assures full cabin ventilation. Use with SCAT-11 ducting (p/n 05-29911) or CAT-11 (p/n 05-29811).