I shipped the item with a security sticker for anti-tamper purpose. Buyer opened a return case immediately after item delivered. buyer uploaded several photos showing the item buyer was intended to return, but that item does not have the sticker.

Buyer even said he would pay to ship it back in Ebay message but buyer never shipped. Buyer refused to communicate and asked ebay to step in.

From buyer's photo, Buyer is a professioal repair service person, he is very clear about why there is a security sticker there.