I have 2 sets of them and love them. After years of fooling with strap on and scew in steps, then stick ladders, I will never go back to anything else. They are small and lightweight and can be strapped to your lock on stand and carried into the woods very easily. You can also call Summit and they will sell you one Buckstep, you know in case you happen to "run over one with your truck" nod, nod, wink wink. It's funny I have managed to run over 2 of mine.
Anyway with this extra step you can get up to around 20 feet which is my preferred hunting height. 5 tseps plus my Headhunter Lite stand weighs right aroun 21#, which is about the same as most climbing stands and very manageable. They way I install mine is to install a haul up rope and strap the Bucksteps at various lengths down the rope and pull them up as I go. They strap on very easily and are very stable once attached.
If you look around you can find them online for less than $90 a set.