Cool pins are just that - COOL! They are heat resistant up to 350 degrees Fahrenheit so you can iron over them without melting the tip of the pin or burning your finger. The large pinheads are easy to grasp and manipulate - perfect for all ages. And since the tips of the Cool Pins are colorful, they are easy to spot and remove - no pins left behind. Cool pins are sharp and fine. At just .5 mm, they will not leave holes in your finished project. 50 pins come in a reusable storage box.