BXXX is a style reference. See the Current Bracelet Designs for examples of other styles.
SNXXXXX is the serial number of a specific piece of jewelry. Not all pieces have a serial number as applying it might damage the piece.
B067 SN20011 is a size 60 which means that it will fit a wrist that is approximately 7."" in circumference depending on whether or not you like a cuff bracelet to be tight or loose. It is made from 18 gauge sterling silver sheet and is 5/8" wide.
If SN20011is not your size, B067 is a Current Design and a new bracelet can be made to fit your wrist. This will require that you contact me by phone or email.