Help with hallmark/quality of silver

Hello, I bought some silver items in Acapulco, Mexico around 16 years ago. One item was an arm bracelet in the form of a snake. I have stored it for many years and I am thinking of selling it but I am not sure of its quality and/or price (I can’t remember what I paid for it). I have taken some photos of the hallmark. Can anyone help with any information? Thanks in advance.