It is the recommended first choice. Featuring a continuous spiral nylon coil, the zipper glides smoothly and flexibly, bending easily to fit the curved edges of pillows. With a static horizontal pull strength of ≥25kg, it withstands daily compression and handling, and endures repeated opening and closing without fatigue, ensuring a long service life. It is also moisture-resistant (never rusts), withstands -30°C low temperatures, and includes UV stabilizers against aging. Free of fluorescent agents, formaldehyde, and aromatic amines, it is eco‑friendly, skin‑safe, and highly cost‑effective.