Hi
As Colin says - these tensioners are very good - but not essential. They will tighten your poles (oo-er missus) to a very high torque, which makes for nice smooth lines in your awning, I must say.
However, like I said - not essential.
What IS essential is that you erect your awning BEFORE you go away! Don't risk World War 3, Armageddon and the 'Big D' with the Missus like what I did.....
EEK!
(Slopes off for a lie down in a darkened room and a rub down with the Sporting Life....)
Mac