Old rubber bushings dry rotted and trapped water causing struts to rust. I also had to replace the brackets. I figured polyurethane would offer better wear resistance than the original rubber. They fit my 1985 Chevy S10 perfectly and should help support the cabin, hopefully even longer than the originals which lasted 27 years and 200,000 miles on a car always left outside exposed to the elements. If they don't, I'll be coming back in another 27 years to lower my rating if Amazon still exists.