You must ship with tracking code and the tracking must say "Delivered", only then you will have seller protection. If the item is valued 750USD or more the signature option is also required, just "Delivered" is not enough in that case. If he does chargeback, you must show PayPal all the shipping documents (which show that you shipped to his adress) and if all goes well then you can keep your money. If he files dispute for item not as described then you'll need to accept the return and hope that the returned item is what you sent, if not, you need to appeal PayPal's decision because they will refund buyer after you have picked up the returned package.
