The speed control lever on your stand mixer allows you to adjust the speed that the mixer is running at. The lever is approximately 3.5 inches long, with a black plastic handle at the top. The speed control lever connects to the interior of your stand mixer, so you will have to take it apart to access the bar that the lever is attached to. Once you’ve opened the mixer, you can unscrew the old lever, taking care not to misplace the screw or washer that holds it in place. Replace the old lever with the new one, and then put the mixer back together.