1. Six bolts are positioned simultaneously, making the siphonic rainwater drainage cover more aesthetically pleasing and raising production standards, resulting in higher precision. Generally, only two or three bolts are used in the industry. 2. The bolts are welded using an Italian-imported welding machine, ensuring that there are no weld scars or burn marks on the rods. 3. The inner and outer walls of the flange are completely machined, making the appearance of the siphonic rainwater drainage flange more attractive, with precise thickness and roundness. 4. The design is reasonable, with the cover and settling height fully referencing the standards of foreign manufacturers, facilitating the formation of siphonic action. 5. Enhanced service, providing ample space for customers to add markings. 6. The settling nut is made of stainless steel and is machined for easier and more straightforward installation. 7. Excellent sealing; the rubber ring is designed within the flange, preventing water leakage. 8. A wide variety is available, including small flat rainwater drains, large flat rainwater drains, and settling rainwater drains. Each specification currently has over 2,000 units in stock and can be customized according to customer needs.