Zinc Yamaha Trim Tab Anode for 150 - 225 HP MotorsA trim tab anode helps counteract the torque that a propeller creates, and levels out "prop-walk," which is a propeller&';s tendency to rotate concerning a vertical axis. Also, trim tab anodes can absorb various types of corrosion, helping alleviate corrosion to other parts of the boat.Features: Designed for 150-225 HP Yamaha motors Meant for saltwater boat use Boat type: Motorboat with outboard Specific: Outboard Specifications: Material: Zinc Weight: (lbs) 1.15 / (kg) 0.52 Dimensions: h: (inch) 3.43" / (mm) 87 ;: (inch) 3.94" / (mm) 100 m: (mm) 10 x 1.25 *Sold as an Individual Specifications:Material: ZincQuick Guide (pdf)