Ever wonder what happens to many race car components when the chassis is continually bottomed out? Spacers are made from a unique material that will not let the engine vibrate under normal conditions yet they "give" a little during bottoming out, easing life a bit on engine and driveline components. 1/4" thick spacers are 1-1/2" O.D. and have a 1/2" hole. Package of 2.