A complete system for ventilating manholes and vertical confined spaces while allowing easy entry and exit, the RAMFAN UB 20 exhaust duct, a space efficient option to a fan, has a saddle vent which allows unobstructed airflow down through the vertical opening. The 15-foot (4.6-m) duct can be attached above or below ground to meet the site’s ventilation needs. The system includes: UB20 Blower/Exhauster, Saddle Vent and Mount, 90-Degree Elbow, Quick Couple Canister, 5 foot x 8 inch (152 x 20 cm) duct, and 15 foot x 8 inch (457 x 20 cm) duct. Be sure to ask about our complete line of RAMFAN products available.