Features: Scope of application: double-layer membrane greenhouse for internal and external top film, single-layer film greenhouse top roll film. Cast aluminum casing: The shell is made of cast aluminum and die-casting, casting in one molding process. Stabilizing screws: The new gaskets are more stable and durable. Comfortable Roller: A new roller that prevents aging and rollers. High-quality iron chain: It adopts high-quality iron chain, which is not easy to rust and has a longer life. Specifications: Condition:100% Brand New Material: Aluminum Color: As shown in the picture Size: Approx.23*16*19cm/9.1*6.3*7.5in Speed Ratio (refers to the gear ratio of the final drive in the axle of the car, which is equal to the angular of the drive shaft than the rotational angular of the axle of the upper axle, which is also equal to the ratio of their rotational speeds.): 4:1 Single Net Weight: 2.1KG Large Roll Height: 1.5 meters Large Reel Length: 120 meters Chain Length: About 3 meters Service Life: More than 3 years Package List: 1*Manual Film Coiler