Bato bobbins are designed to hang from the overhead crop support wire. There is a locking tab in the hood to help secure the bobbin on the wire and keep them from popping off. They come factory wound with 42 foot of white twine. Due to the UV stabilizers, Greenhouse Wire Bato Bobbins can be rewound and reused for several years, but because they are priced so economically, and for sanitary purposes, it is best to replace them each crop.