My back yard is on a slight grade, and I always dreaded cleaning the gutters, etc.  I used to put flat stones or wood under the right leg, to make up the difference, and it was never exactly the proper hight.  These stabilizers are great, they adjust to compensate perfectly for un-level ground.  I had to drill out the rivets of the original feet on my ladder, to remove them.  But drilling & installing the stabilizers was fairly easy.  The instructions were pretty good.  I wish I knew about these a long time ago.