4 Sets: You will receive 4 sets A4 D rings binding spines combs at the same time, each set comes with 2 pairs of screws and 1pcs clip ring binder. Adequate quantity for both personal and office use. 3-Ring Binder Mechanism: Designed as the perfect A4 notebook mechanism replacement kit, this 3-ring binder mechanism allows for easy organization and binding of your loose leaf notes, planners, and documents. Iron Material: Made of durable iron materials, our 3 hole ring binder mechanisms feature robust metal clips that ensure long-lasting performance and reliability, making them an essential addition to your binding accessories. Easy Installation: This binding spines combs set comes with all necessary components, including screws and nuts, allowing for a seamless setup and secure attachment to your notebooks and planners. Compact Design: Measuring approximately 4.7cm in width, 28cm in length, and 6.1cm in thickness, along with 4cm inner diameter of ring, this binder mechanism is designed to accommodate standard A6 loose leaf pages, making it ideal for personal organizers and stationery lovers.