C & F Design Bobbin Holder - Standard (CFT-60)Standard size tubes can be used for threads of various sizes. Holds the material firmly when you release your hand while tying with its own weight (17g). A micro slit foam is set at the entrance to prevent the thread from coming off the tube or getting entangled with the arm by applying appropriate tension. The Teflon painted integrated arm has a smooth bobbin rotation and stable tension. Uses ceramic (zirconia) tube Dedicated bobbin threader included