eBay has a money back guarantee for buyers. If the buyer says what you sent them isn't exactly what you said it was eBay will refund the buyer, force you to pay return shipping, and reverse your PayPal payment.
Notice I said "if the buyer says" which means they can lie. Also what the buyer actually sends you back is irrelevant. The process is mostly automated and whatever you tell eBay will be ignored. They will side with the buyer and you will refund them.
If the buyer is a decent person you might actually get back the item you sold them in functional condition and if they aren't you won't even get that back.
Notice I said "if the buyer says" which means they can lie. Also what the buyer actually sends you back is irrelevant. The process is mostly automated and whatever you tell eBay will be ignored. They will side with the buyer and you will refund them.
If the buyer is a decent person you might actually get back the item you sold them in functional condition and if they aren't you won't even get that back.