This was very useful when I wanted to make fine adjustments to the length of my curtains. There are 3 items listed, but it's possible to increase the quantity. You can add up to 5 items at no extra charge, so please comment before purchasing m(_ _)m Length: 80mm Adjustment: Approximately 5mm per increment, adjustable by approximately 50mm. [How to Use] Place this item as shown in photo 2. You can adjust it by sliding the curved part on the right side of the photo downwards.