The difference between them is the Pure Sine Wave inverter produces a better and cleaner current. They are also considerably more expensive. You might find it practical to get a small Pure Sine Wave inverter for any special need you may have, and also a larger Modified Sine Wave inverter for the rest of your applications.
Elm Trees can live over 100 years in their natural environment.
What bug is eating my Elm tree ? If you have damage to the leaves of an Elm tree in south eastern Australia, particularly Melbourne or Victoria, it is most likely to be Elm Leaf Beetle Damage. If whole leaf sections are being eaten that is usually possum damage.