【Product Advantages】The bracket and keel of this boat trailer keel roller bracket assembly allow for quick installation and disassembly, saving the users time and labor costs.With a good reputation for long service life, strong durability, and not easily damaged, the roller assembly kit's sturdiness and durability can optimize your boating experience.,【High-quality materials】Our boat trailer roller brackets are made of high-quality steel plates and the rollers are made of high-quality rubber. These material features enhance sturdiness and prevent rust, ensuring long-term use.,【With Mounting Bolt】Dimensions of mounting slots: 0.5 inch wide; bolt size: 4.19in(L)*0.46in(W); thread length: 2.11 inch. If the included mounting bolts don't fit your trailer's holes, you need to purchase additional bolts.,【Product Size】With the bracket measure at 12 inches long, 6.1 inches wide and 3.5 inches tall, each installation slots measuring 0.5 inch wide and 4.9 inches long; and the roller size is 11 inches long and 3.2 inches in diameter.,【Wide Scope of Application】Practicality was fully considered when designing the marine trailer roller to be suitable for various ships such as small yachts, fishing boats, commercial ships, etc. It can effectively reduce the friction and wear between the ship and the trailer and greatly extend its service life.