Can I bring Westin's room card?

As long as you don't check out, you can take it with you when you go out, but you'd better be careful not to lose it

If you need to charge the room when you leave the room, and you are worried that the room will not be able to supply power normally after the room card is taken away, you need to ask the front desk for a charging card separately. If you want to take the card out of the hotel after check-out, you need to see if there is a word on the back of the card to compensate for the loss. If you don't specify it, you can usually take it away. People who go out and stay in hotels are all like this. Half of them will consider taking things from the hotel, and half don't know that the hotel still has these things.