This cost-effective hood is intended for small facilities or installations in which a number of hoods are needed. The translucent acrylic door travels on a track featuring stop pins for open closed or intermediate positions. When closed a small space at the bottom of the door permits continuous airflow. Stepped stack allows use with 12 cm or 15 cm (4 or 6) diameter duct and can be connected to any air-evacuation system.formula for calculating required air flow for hood 1.833 x 150 274.95 CfM.front opening dimensions 56 cm x 30 cm H (22 x 12H). footprint 69 cm x 33 cm x 56 cm H (27 x 13 x 22H).Shipping weight 17 kg (38 lbs).Economical polyethylene constructionCurved inner corners allow efficient airflow and easy cleaningChemically resistant spark resistantIdeal for schools junior colleges and universities