Metal hardware for hooking hook 3911 antique boots or lace-up laces in climbing shoes, trekking shoes, etc. There are many eyelets used in the shoelaces, but when viewed from the side, this product has a hook shape of a Katakana Katakana. However, since the inner diameter of the U-shape is about 0.1 inch (3.5 mm), it is not suitable for use with too thick shoelaces. If the string is thicker than 0.2 inch (4 mm), please consider the 414 key hook with a triangular ring of about 0.2 inch (6 mm) on each side. In addition, since the shaft length extends from the main unit is approximately 0.2 inches (5.5 mm), please handle the total thickness of the leather and other items below 0.1 inches (3.5 mm). The product is called "key hook", but rather rather than a hook is similar to a grommet stud. Place the included donut-shaped flat washer (washer) from the back and fold the 0.2 inch (4.5 mm) thick shaft to tighten it. Numbers are approximate. The color of the actual product and the color of the posted picture may differ depending on your monitor.