Material: pen holders are made of manganese steel that is durable, flexible with long lifespan and therefore they are not easy to get rusted and erodedAdjustable loops: the diameter of the spring loops can be expanded from 7 mm to 18 mm; You can use them to hold almost any size of pens or pencils with the useful pen holderPractice design: these pen holders match with your favorite notebook very well, and they are lightweight and easy to carry to everywhere, which solves the trouble that you often lose your pensWidely use: these pen holders are suitable for students, teachers, postmen, doctors, nurses, pilots and other careers; They can be applied at home, school, office and also suitable for those who need to carry a pen at any timeDesirable gift: there are 12 pieces of pen holder clips, which are enough for your different needs, and you can share them with your family friends and colleagues