This 3-blade outboard propeller is designed as a direct replacement for selected Mercury and Mariner 135-300 HP outboard engines with a 4-3/4" gearcase and right-hand rotation. It features high-strength aluminum alloy construction for durability in both freshwater and saltwater use. The 14-1/2" diameter and 19" pitch are built to deliver strong thrust, smooth operation, and improved cruising efficiency. An internal rubber hub helps reduce vibration and protect the engine from shock loads. An M21 interchangeable hub kit is included for easier installation.