This Seattle Seahawks mug is glass, a sturdy and heavy duty beer stein. In doing research, haven't found this exact mug. This leads me to believe the owner will likely have a unique mug not owned by your neighbors. There is a 17 stamped on the bottom. Would be confident this is at least 16 oz if not more. This is built with quality and will hold a cold beverage cold or maintain a hot coffee. As Matthew works in health-care, be aware, this isn't light weight so would not be good for the frail unless used as decor. Verified November 21, 2025 Long Shelf right side of the shed below white two level shelf