O-ring dampens noise and vibration and holds the nut in place. Stabilizes the propeller by providing a larger contact point. Black prop nut for trolling motor reduces noise and vibration of the propeller. Replacement of support nuts and washers provides smoother, quieter, flex-free operation and reduces wear and tear on the trolling motor and battery. Includes built-in cooling ports to lower operating temperatures and extend battery life. Trolling motor black prop nut is machined from 6061 billet aluminum with anodized protection for durability. Built-in cooling port reduces operating temperature and extends battery life. Easy to install: no tools required. Features easy-to-grip knurled edges. O-rings stabilize the propeller by providing a larger point of contact. Reduces propeller noise and vibration. Remove the existing propeller nut and washer. Hand-tighten the eliminator so that it fits snugly against the propeller face. Note: There is a spacer on the back of the eliminator that will expand over time, so do not overtighten. Material: High-quality aluminum billet with black anodized finish, rust-resistant and long service life. Application: Compatible with: GFEL-MG-R-DP Note: Not compatible with Hydrilla Hacker Props. Color: Black Material: Aluminum Package Contents: 1 x Trolling Motor Prop Nut Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the actual product. Measurement may vary by +/- 1-3 cm.