These Mainstays Clothespins in particular feature a sturdy, galvanized, rust-resistant wire springs which means that they can handle the day to day use and multiple different climates caused by the weather. The wood was specifically tested and made of a stain-proof hardwood which is great when working with clothing or items that may not be so clean at the initial time of use. The Mainstays Clothes pins are specified at 72mm, which is a great size and has the strength needed when in use.