I wouldn't recommend using an extension for the pole saw. Just lifting it up and seeing the heaviness pulling the shaft down to make a slight arc I could easily see how the pole would get damaged from a quick movement of lowering or raising the pole from momentum. Either hiring a tree climber, using a manual pole saw with or without a ladder or choosing to drastically make shorter cuts from the base or totally eliminate a tree I'd say would have to be considered if the basic 12 foot Echo pole saw cannot handle the job.

looks great but did not get to use it yet just to cold im sure it will be a big help in getting to my higher branches .will buy from saw suppliers again thanks Alan.