This is a vintage Coach Shoulder Sac, style 9730 from the late 1980s. Medium brown leather. Serial number 088-6117. Made in the USA. It does not have the hang tag. It is in very good condition, showing extremely light wear on the edges. There is one white mark on the inside above the serial number. The strap length is a little longer than what was normally used on this style, it might be a replacement, but it matches the bag perfectly. See last photo.
Height top to bottom - 10 inches
Width across - 10 inches
Depth front to back - approx 3.5 inches
Strap total length - 55 inches