The Air Intake Vent with Shutter, for use in conjunction with an exhaust fan, allows controlled airflow through your greenhouse. May also be used as a free-air exhaust. Usually positioned in a high location in the lowest panel in the front wall. This is a motorized vent, and comes pre-wired with a 9 foot plug-in power cord with 3-prong plug. No electrician needed. Ships fully assembled out of the box so you're up and running in no time! 16" is recommended for RIGA 2, 3, 4, Junior Victorians, Victorian VI 23-24 greenhouses20" is recommended for RIGA 5, Victorian VI 34-46 greenhouses24" is recommended for all RIGA XL greenhouses Inlets are an essential part of your complete ventilation system. They bring fresh air into your greenhouse, barn, or building where it is properly mixed and then circulated and exhausted. A well designed and well located inlet system is as important for good ventilation as the exhaust fans themselves. FEATURES 18-gauge heavy-duty housing with welded corners for extra strength Rough Opening:16" - 16.25" x 16.25"20" - 20.25" x 20.25"24" - 24.25" x 24.25" Motor Electrical SpecificationsPower Usage: 58WWhen wired for 115Vac: 0.5 AmpsCan also be wired for 230Vac: 0.25 Amps Comes fully assembled out of the box 3-prong plug and pre-wired for 115 Volts. No electrician needed for install! High-efficiency aluminum shutters with tie bar to reduce shutter flapping and opening on windy days Nylon bearings and solid shafts for smooth performance Interlocking louvers for maximum weather seal Financing Available Installation Instructions Motorized Air Intake Shutter Instructions