I've had my AW18 for a couple of weeks and I just noticed a document on my computer called Accidental Damage Coverage Agreement. Is this something that came with my warranty, or is this something that I need to upgrade to? If it is something I need to buy separately, how do I buy it, and is it worth it? I'm very careful with my device, but since I spent so much money on it I thought it might be a good idea to add some protection.