Exactly what I needed to use with my pump jacks! provided me a good stable platform to work from. I have not test them at there full extension, yet, but it work well when I needed to cantilever 4' out over a roof, when extended 80%. Don't take that as, a recommended way of using! I'm sure the manufacturer would say that it was in "improper" use. I only use it as an indication to say yes it is strong and sturdy, if supported and/or braced well.