it may be simple but it is effective to have this item when asked poles or one wants that its construction is well posed. need to turn your spirit level in all directions. casually you save time. the object is magnetized, so easy to land on an iron pole. if your building is not scrap, do not worry there is a large elastic which is sold with to maintain it. (By cons, I have not yet understood how the elastic is attached with the hook ...) Small, sturdy and lightweight, it is the object to be !!
in addition it is the silverline quality, so LIFETIME WARRANTY !! : D
PS: Do not forget to sign up on their website for the guarantee. if it does not fit, you can register later, but at least it's done because they require the purchase date.