A control arm bushing is a device that helps keep the arm from bouncing during suspension movement. It's located on the suspension member near the axle and helps to reduce shock loads. Control arm bushings can also wear over time, so it's important to replace them as needed.

If you're like most drivers, your car's control arms are probably going to need bushings at some point. But which ones? Here's a guide to buying the right control arm bushing your car.

The first thing to consider is the orientation of the control arm. Most cars have left and right arms, but there are also cars with front and rear arms. The orientation of the bushings depends on this orientation.

For left-side-oriented cars, you'll want bushings that fit in the "front" or "rear" channels. For right-side-oriented cars, you'll want bushings that fit in the "left" or "right" channels.

Next, you'll need to decide on the diameter of the bushing. Most control arm bushings come in either 1/2 inch (12mm) or 3/4 inch (19mm) sizes. The larger size is better for high-performance applications, while the smaller size is better for everyday driving.

Finally, you'll need to choose a bushing material. There are several types of materials available, but high-quality bushings usually use either rubber or metal inserts. 

Once you've determined all of these factors, it's time to buy your bushing kit.