Our gear ratio of 4:1 makes using this greenhouse hand crank easy to use. Once installed, you can simply rotate the handle to easily roll up the side of your greenhouse to properly vent your plants and achieve optimal airflow. Our manual hand winch is weather resistant. It can be left out in the rain, snow, sun, or any other inclement weather. Guaranteed to have a long use life, you can count on our greenhouse hand crank year after year. Our greenhouse vent opener winch is engineered from stainless steel, making it extremely durable. No matter the size of your greenhouse, our hand crank will work flawlessly, ensuring a stress-free gardening experience for you. Our manual winches can be installed quickly and easily. Once installed, use is a breeze. Depending on the installation method, you can use our hand crank in different ways. Works great as a manual hand winch for shade cloth. Our manual winch small is the perfect tool for simplifying the process of rolling up your shade cloth or greenhouse.