The commonly used ropes for scratching posts are sisal rope, jute rope and cotton rope. Sisal rope is the most durable among them..Compared with other repalcement posts, our 4mm sisal rope and 3mm cardbord tube are thicker, so it is stronger and more durable..Compared with buying rope and winding it yourself, our products not only wrap it more tightly, but also save your time..This cat scratching post is suitable for M10 screws. If your existing cat tree uses this type of screws, then you can choose this repalcement poles. We have two types of posts: M8 and M10. Please carefully confirm the type you need before placing an order to avoid buying the wrong one..Each item contains 2 replacement posts, 2 screws, 2 bolts, and 1 Allen key. Our products come with more parts than others, making installation easier and faster..We have 14 options: M8 25cm, M8 30cm, M8 35cm, M8 40cm, M8 45cm, M8 50cm, M8 55cm and M10 25cm, M10 30cm, M10 35cm, M10 40cm, M10 45cm, M10 50cm, M10 55cm. Please confirm your selected option before purchasing. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.