100% Cotton Size - 3.8cm in length,3.6cm in width / 1.5 * 1.4 inches. Durable Plastic: Plastic bobbins are stronger and waterproof than cardboard bobbins can reusable for many years. Flat shape with smooth finish and not easy be bent, so the floss doesnt snag. Unique Design - There are two thread clips on each board to keep the end of the line stuck, also you can labeled these with marker pen for easy reference. Organize Thread-Thread bobbins perfect to keep remaining thread, skein, washi tape organized, untangled. Easy to label them with marker and ready for your next using. Wide Application - Help you to save thread, skein, washi tape,let you convenient to use, in case various threads will be in chaos.