The stabilizer itself must be mounted over the centerline of steering stem or pivot point of the forks on a motorcycle, unless you are using linkage that accomplishes the same goal.
When ordering a stabilizer only, it will normally come with a standard link-arm, as shown in this picture, that matches the stock bike components that you are ordering it for.
Some applications require different lengths and shapes of linkarms due to physical hurdles and depending on the clearances for your particular application.
When buying a stabilizer only it's a good idea to give us as much info as possible in the notes section of the check or specify how you want the link-arm mounted, if you know what you want. The picture shows a "standard" mounted stepped link-arm.
Be sure to mention it's a SUB mount or LOW mount or any special features or mounting items you are going to be using, so we can hopefully provide you with appropriate parts needed. For special applications or questions regarding the purchase of a stabilizer only, we recommend you call or email us. We're here to help!!