Shenzhen Hongfa Automatic Door Co, Ltd. places great importance on raw materials used in the manufacturing of spiral door-6ft roll up door. Each batch of raw materials is selected by our experienced team. When raw materials arrive at our factory, we take good care of processing them. We totally eliminate defective materials from our inspections.. We receive important feedback on how our existing customers' experience Hongfa brand by conducting customer surveys through regular evaluation. The survey aims to give us information on how customers value the performance of our brand. The survey is distributed biannually, and the result is compared with earlier results to identify positive or negative trends of the brand.. We pride ourselves with outstanding services that make our relationship with customers as easy as possible. We are constantly putting our services, equipment, and people to the test in order to better serve customers at Hongfa Automatic Door. The test is based on our internal system which proves to be high efficiency in the improvement of service level..