Our SCX10ii Differential covers are machined from solid brass. Why do you need a brass diff cover? Two reasons; 1. More added weight down low to help lower the center of gravity of your rig, and 2. Better bearing clamping force that is more evenly distributed versus the stock plastic housings! Diff covers can easily be painted or powder coated to the color of your choice. Drilled and tapped to accept the stock hardware. Weight = 1.1 ounces *Each order will receive one SCX10ii differential cover only. Parts in picture are for reference only.