- Widely compatible circular end caps for metal chair heads, furniture, tables, bicycles, boats, fence railings, and can also cover screws and bolts. They fit any circular tube and provide protection to prevent damage to the tip and tip rod. - Easy to use: select the appropriate nut inner diameter and length. It is recommended to choose a nut slightly smaller than the outer diameter of the item to be protected. The thread protector safety cover can be trimmed to the desired length. - High quality material: made of vinyl flexible rubber, wear-resistant and durable. The thread protector offers excellent flexibility and insulation performance, plus a sturdy structure that effectively absorbs impacts. - Product size: Rubber end cover combination kit includes 9 sizes (2 x 16mm, 3 x 17mm, 4.5 x 17mm, 6 x 17mm, 7 x 17mm, 8 x 18mm, 9.5 x 17mm, 12 x 25mm, 20 x 27mm). - Use scenarios: 1) Protect chair legs, furniture hardware, and table fittings from impact and wear during moving or storage. 2) Cover exposed screws and bolts on fences, rails, bikes, or boat fittings for safety and a neater appearance. 3) Shield ends of round tubes on boats, furniture, or gear during transport to reduce damage. - Benefits: provides functional protection, compatibility across a range of circular tubes, multiple size options for a precise fit, durable and flexible material that cushions impacts and insulates.