Nobody ever replied, so I bought the thing. Great idea, but VERY poor execution. Needed so many modifications for it to function properly. Don't recommend it unless you're willing to do some modifications.
1) The silo extenders don't stay on worth a darn and always fall apart, spilling feed everywhere... had to screw each section together.
2) The straps and bracket used to mount it are cheap plastic and I don't trust it at all... added metal straps since it's supposed to hold quite a bit of feed with an extender or two on it.
3) The chickens easily scooped all the feed out, so added a plate so chickens couldn't easily scoop it out anymore.
With all the fixes, it's a great way to hold a lot of feed and keep it relatively dry. Sucks big time if you use it as is. Just putting this out there because this is what I wanted to know before buying it.