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. Acts as a heatsink with built-in cooling ports to lower operating temperatures and extend battery life. Black prop nut is machined from 6061 billet aluminum with anodized protection for durability. Built-in cooling port reduces operating temperature and extends battery and motor life. Easy to install: no tools required. 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 expands over time, so be sure not to overtighten it. Material: High-quality aluminum billet with black anodized treatment, rust-proof and long service life. Compatible with GFEL-MG-R-DP trolling motors. (Note: Not compatible with Hydrilla Hacker Props.) Color: Black. Material: Aluminum. Package Contents: 1 x Trolling Motor Prop Nut Eliminator. Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. Measurement allowance: +/- 1-3 cm.