These retainers fit most metal and plastic spools and spools. Install the spool on the corresponding thread. Lock the spool to the corresponding spool. With these plastic parts, the needle and thread will always be together, making your sewing projects easier. The possibility of winding the spools and each spool saves time when searching or unwinding loose spools. Keep Your Sewing Supplies More Organized The spool pin is made of high quality plastic, providing good durability and stretchability for long term use and repeated use. Spool holder HOW IT WORKS: These spool holders snap securely inside the spool body on one end and inside the spool body on the other. It works with M, L and A size spools and is adjustable to fit different spool diameters. Material: Made of high quality plastic, lightweight yet sturdy and durable with ductility shatterproof for long term use. Color: purple, blue, rose red, green Size: 70*20*4mm Package Content: 50 clips, random color