I'VE READ SOME OF THE REVIEWS THAT WERE NEGATIVE BUT THEY WORK VERY WELL WHEN INSTALLED CORRECTLY. MY TONNEAU HARD COVER IS VERY HEAVY AND THESE SHOCKS WORK EXTREMELY WELL TO LIFT AND HOLD THIS COVER. AND THEY ARE HIGHER THAN MOST OTHER SHOCKS BECAUSE IT'S A PLUS WHEN YOU TRANSPORT BIG LOADS ON YOUR TRUCK! FIVE STAR RATING IS HERE!