Fit perfectly on a Drive brand walker. Not sure about other brands. They all seem to use a standard size of tubing, but the locking button mechanism for adjusting height may differ.These are exactly as advertised. They have a longer length than the original/standard legs on a walker, enabling you to extend the height of the walker so the person using it can stand more upright instead of hunching forward. This package includes BOTH the front legs with wheels as well as the back legs with the rubber feet. This was exactly what we needed, excellent value, so much better than buying a new walker.I bought these for my husband's walker that he used following knee replacement surgery. He is 6' 1 " and the standard walker was not tall enough to allow him to walk upright. These extensions will fit any standard walker; just a matter of removing the old ones, sliding these on and adjusting to the appropriate height. For his height there was still room to adjust them 2" taller.Perfect extensions for my dads walker. He’s over 6’. Sturdy and well built legs. Increases his walker height to more comfortable level for him, that we couldn’t get with normal walker legs.I find four-wheeled walkers useful although I need to be careful the walker does not get out of control. Drive provides excellent walkers and accessory wheel sets.The first set that we received had wheels that were VERY noisy. Of course, as soon as I requested a replacement the wheels were better. When the replacement arrived, the legs did not fit onto the walk, despite the fact that they were supposedly identical to the original set. So I returned the new set and hope that the old wheels will continue to work quietly!I ordered this pack to go with the walker I purchased to give me the additional wheels and extend height if required. The individual pieces are finished nicely but are not square. Meaning of "square" is position of extension holes in relation to wheel axels. The wheels are aligned approximately 10 degrees off so the walker wants to "creep" to the left and needs constant lifting and realigning. This could be a major problem for someone of poor mobility and cognitive function. The tubes and wheels that came assembled on the walker are fine.These were as advertised. Complete set of walker extensions (4 piece set). Great for my tall uncle. He can walk upright now and not hunch over. He was very happy with them. They were easy to install on our Drive walker.