Metal compact casing with high fire resistance, easy for installation, cleaning and maintenance.n ? This type of air curtain has piano-key control and remote control, with high-low speed adjustment, applicable to requirement at different places.n ? The structure of centrifugal vane and vane wheel and the design of effective worm case achieve optimal performance of the fan.n ? Computer-based optimized design of motor is reliable performance, with continuous operation of over 5000 hours without failure.