Brocraft Boat Launching Wheels/Boat Launching Dolly 12" Wheels For Inflatable Boats & Aluminum Boats Constructed of marine grade aluminum square tube with CNC processing, Angled frame arm Desgin , will not conflict the motor Weight Capacity: 500 lbs.Pressurized wheels; 12" in diameter Wheels easily lock up when not in use and easily fold down for boat moving Push the stainless steel solid button to operate, Auto lock wheel arm system by Easy Sliding Transom Bracket Includes two years warranty