Prym Plastic Sew On Snap Fasteners are available in 5 different sizes ranging from 7mm up to 21mm in either black or transparent. These fasteners are a convenient choice for various sewing projects. They can be easily sewn onto fabrics, providing a secure closure. The fasteners are made of durable plastic and are designed for long-lasting use. Available in packs of 18, these snap fasteners offer excellent value for crafters and sewers.