1. Exhaust Fan For Evaporative Cooling Pad System We have two models to be choose: 1380x1380x450mm and 1000x1000x450mm Model Diameter Blades Blades rotational speed Motor rotational speed Air flow Total pressure Noise decibels Import power Rated voltage High Widh Thick Fan-39'' 910 mm 438 rpm 1400 rpm 21000 57 <=65 550 380 1000 1000 450 Fan-54'' 1250 mm 437 rpm 1400 rpm 44000 57 <=65 1100 380 1380 1380 450 Centrifugal Shutter System Exhaust Fan (Auto push-pull type exhaust fan) 2.Details Blade: 3 types of material for choose: stainless steel/aluminum/galvanized sheet. Adopting a punch forming technology. Chicken House Ventilation Fan Wall Mounted Centrifugal Shutter Exhaust Fan Centrifugal Shutter Exhaust Fan with Push-pull Device and Automatic Belt Tensioner Frame: adopting advanced automatic manufacturing process, made of thick galvanized sheet. Shutter: made of hot galvanized sheet with thickness 1.0 and 1.2mm, to increase the quality and the stability while working. Motor: both China high quality motor and Siemens motor are available. Aproved by CCC certificate, protecting level: IP55, insulation level: F class. V-Belt: imported from Japan and Korea. Resistance to abrasion, without deformation. Centrifugal system: adopting high-class nylon mixed with amount of fiber glass. All parts are connected by rivets. This system will be assure to open the shutter with 90 degree when the fan working. Fan belt pulley and flange: made of high aluminum-magnesium alloy by die-casting. Light weight, low vibration. Blast-sanding treatment for attractive appearance, eliminate internal stress to improve its own rigidity and stability.