I bought one of the hand-held kits and a new nose cone for my Stihl 600 backpack. Some heat gun work and pop rivets made the connection between the two. With two tubes and a couple 90s on the end you can get it pointed in the right direction but it's really bendy and hard to manage at anything barely above idle and you will get covered in gunk. The original pistol grip/tube discharge doesn't really lend itself to being pointed up with the extension since you can't really reach too far beyond the end with the left hand to support the extension. Might be better if you took the original slider assembly apart and moved the connection closer to the grip. I went back to my old method of getting on the roof and doing it directly with the backpack, still a huge mess on the ground when I was done.
I installed the Stainless Gutter Guards on everything and have been happy so far. We have a lot of cedars and some needles and small pieces will lay on top and drip over the edge but it's still way better than cleaning out the slop.
