Whirly
Most probably uinder your seat in the aircraft there is a blue covered book. It's called the "flight manual". It should have all the information you need.
If you haven't got a flight manual and are looking at buying an aircraft - ask the person whose aircraft you are looking at buying to lend you their copy.
If you are looking at a new machine, your local Eurocopter dealer will be more than happy to do a comparison for you.
Your question is a little too general to give a detailed answer.
