Luckily PayPal provides some protection as well.
You can definitely protect yourself against a non-delivery claim yes. Significantly not as described claims by unscrupulous PayPal users are always available. eg you sell an A1200 060/PPC card...buy claims that he only received a 4mb A1200 RAM board.
In this case the buyer is told to send back an item (and the timescale is too short of international postage) and once some sort of tracking number proves something was sent PayPal release the funds held into the buyer's account.
So you end up with no money, no PPC card, and a 'free' A1200 4mb RAM board. PayPal always take the buyer's side in these claims, and as the buyer claimed to have received an A1200 4mb RAM board all he has to do is take a picture of it.
Now you know why I never sell anything more than 5 quid via PayPal to international destinations.