Bookend rubber dam, also named as spine type rubber dam, has obvious fins on the dam body to form a rising angle when the dam is inflated. It is made of high strength canvas as the reinforced framework and synthetic rubber fixed to a reinforced concrete foundation using clamping plates and anchor bolts. In dry seasons, the rubber dam is inflated by air or water to retain water for industrial, agricultural and living water demands; in rainy seasons, the air or water in the sealed bag can be deflated out to release floodwater from river course. Bookend rubber dam heightens overflow's water head and eliminates vacuum underneath the dam to reduce the vibration and abrasion. It is usually used to retain water, agricultural irrigation, generate electricity, control flood, beautify environment, etc. Specification Material structure: one cloth two rubber, two clothes three rubber, three clothes four rubber, etc. Color: blue, black, red, gray, purple, etc. Medium in dam: air or water. According to installation method: Single anchor. Double anchor (pillow-like dam and inclined dam). According to anchored method: Bolt anchored. Wedge anchored. Customization can be available. Feature It can be resistant to vibration, abrasion, dirt, sediment, sedimentation, sunlight, heat, ozone. It has smooth surface with spines, can eliminate vacuum underneath the dam, can create a beautiful scene of waterfall. Automatic inflation and deflation system provides the dam excellent control of height and air pressure. Vulcanization molding one time, increase the lateral tension of dam bag.