Great instructional vid on the cambium/friction saver Ekka.
I remember the first time i used mine, i put my rope through the big hole first as i had forgotten about the retrieval process.
Tree was a pine, about 15m tall, came time to retrieve the saver and deck the spar, pulled on the rope (no throwline attached either) and "hey presto" saver stuck at the top of the tree with the terminal end swinging in the breeze.
I then spent the next 15min perched on top of my extension ladder trying to hook it down with my Jamieson pole, all to no avail.
So i had to climb all the way back up on just one flipline (only had one at the time), by then the tree was bleeding like a mofo.
Moral of the story, brandnew work shirt ruined, but valuable lesson learned.