Custom as in no aurion has them yet but they are available . Best things about slide. You can choose your custom spring rates. Free pillowball mounts Free dust boots. Choice of thickness with dampner oils. 2 years warranty and all parts are sourced from australia so easy to fix :) Slide do heaps of stuff for seat, wheels to turbo kits Brands like Gready Kranze Weds Takata Etc Check them out www.slideindustries.com.au