Absolute rubbish. After less than 27,000 miles of service, the nitrogen gas is completely gone and there is no damping effect when the shock absorber is compressed. They were installed on a 1998 Mercury Marquis with factory Ford HD suspension. The car is used 99% in the city and rarely has more than one person in it. There must be something wrong with this design as they are reduced from $163 to $36. Obviously, Monroe was built by a loser and they want to throw it on the market. We ship them back to Monroe with a lifetime guarantee, but we expect them to find an excuse to deny our claim.