There are two thread clips on each board to keep the end of the line stuck.
Made of plastic, sturdy to use, not easy to break and deform, very convenient to handle and long-time usage.
This set of thread cards can help you to organize and untangle the remaining threads, store needle craft easily, preventing them getting twined, , also you can labeled these with marker pen for easy reference, easy and convenient for classifying.
White floss bobbin size is approx. 3.6 x 3.8 cm, proper size for you to use.