These Butterfly Ear Nuts are made of silver-plated 316L stainless steel and measure 4.5x6mm, making them a strong and sturdy fit for most post earrings. They come in a convenient quantity of 1, 2 or 5 pairs, so you can choose the amount that best suits your needs. With their classic rectangular shape, these Ear Nuts provide a secure backing for your earrings and are sure to be a valuable addition to your jewelry making supplies.