Have owned them before and they fit well and last a long time.
The new ones with different fabric and for those of us not needing double knee protection are great.
It works fine on a flat surface but if the gas bottle has a welding ridge or any disruption of the surface on it like mine does in the middle, it won't measure at that point, and since the orientation of the measuring device is vertical you can't turn it on it's side to use it. Flat surfaces yes 5 stars
The new ones with different fabric and for those of us not needing double knee protection are great.