We offers SQUARE to RoundRound to Round opening for Inlet and outlet . Our Std. models are 100 mm dia150 mm dia.200 mm dia and 250 mm dia, 300 mm , 350 mm up to 850 mm ( also we made as per customer requirements) Air tech engineering Design of all models are based on Direct Gear Motor with Chain Sprocket drive. We manufacture wall thickness of shell 5 mm to 12 mm.