求问“buffer cards”与普通显卡有什么区别？

我在ebay上看到有卖RX 5700 XT，价格也不错才$175，但是说是“buffer cards”，请问与普通显卡有什么区别？

原文如下：

Cards in good working condition, some may have dust/flake on heatsink. 

These cards are buffer cards that came back from ASRock RMA swapped. 

Some cards may not have the original box*