Plant clips are used to support the weight of the plant when they start to get to there mature size. The back of the clip goes on a piece of twine then around the stem of the plant. The clip is designed to hold the twine tightly and won't slip. The clips are a must with heavy plants like tomatoes and cucumbers. You can also use these clips for your flowers and other tall vine and stem plants. These clips save you time and are easy to use and reusable.