Packing: 4 sets (2 sets each of M8x45mm and M8x55mm) Material: Metal M8x55mm size: 22mmx55 mm / 0.87x2.17inch M8x45mm size: 22mmx45 mm / 0.87x1.77 inch Sturdy, not easy to crack or during use. Clear threads, not easy to come off, easy to install, can be installed into your rocking chair without replacing the rocking chair together. Perfect replacement for old screws, extend the life of your furniture, plays a big role in furniture, simple but practical. Suitable for rocking chair bearings, rocking chair accessories, wide range of applications.