I had a job to restore & paint (2) badly weathered, 6 over 9, double hung windows of a historic house. The tops of the windows were about 12' off the ground and the bottom's about 6'. Due to a space limitation from a nearby driveway, setting up scaffolding was out of the question. The amount of work that had to be done also ruled out working directly off of a ladder, so ladder jacks and planks were my only option. I didn't have any so I shopped around and found the Werner's to best fill the bill for me. They will attach to either the front or back's of (2) extension ladders, will easily adjust for multiple angles and will accept plank or planks, up to 24" wide. The other brand I looked at (I forget what that was) only accepted planks up to 18" wide. That difference was a major consideration for me since I generally fall into the "more is better" category when buying tools & equipment. And after actually using the ladder jacks on the job, I was glad that I went for the extra plank width capability. It made for a comfortable work surface where I could move my Frankenstein-sized 12 boots around and feel like I had a wide, solid, footing, surface. Moving the jacks and planks up & down the ladders, as needed, was easy to do and the angle adjustment feature also worked equally as well. Found no fault with these at all.