Automatic mediation belt device, no artificial operation for belt adjustment. Distorted punching blades, with dynamically balanced and static balance test, and engineered design blade to ensure that the blade have a good air flow, great noise reduced. High-tech stainless steel shutters, has a unique pneumatic switch structure to ensure fully automatically open and close the blinds, the shutters achieve wind, rain, dust efficiency. Rotated palm belt use support, access to farm-specific. About XL company: Qingzhou Xiangli Light Industrial Equipment Co.,Ltd has been focusing on ventilation, humidification and heating equipment. Our company is located in Qingzhou, Shandong province. We have passed through ISO9001:2000 Quality system certificate and European CE certificate. At present, our company can produce poultry fan, exhaust fan, gardening fan, circulation fan, circulation fan, evaporative cooling pad, automatic fuel, coal, electric heater, which contains 10 series of more than 100 varieties of specifications. And now the production capacity is 30000 pieces(sets) ventilation and cooling equipments 20000 pieces of heaters.