so basically derlin, or same product but different name, its harder then alliminium but also more brittle. either way... will transfer just as much NVH and do the job just the same.
hell you can use anything. the whole gain is from raising the subframe and using a stiffer bush. I have a mate who has gont the right tight arsed option and cut the top off the stock nissan bushes til its flush with frame and then welded a flat steel washer to the frame and the steel crush tube. effectivly locking it. then bolting it all back up.
works just as well. but too dodgy for my liking haha