USP Alcatraz Inmate Mugs, Set of 2 Reproduction Mugs based on the Tin Cups Used by Prisoners at the United States Penitentiary Alcatraz (1934-1963), San Francisco, California. Food Grade Stainless Steel (304 grade, 18/8). Dimensions: approximately 5" wide x 4" deep x 2.5" tall. You will receive the 2 mugs pictured. Excellent Condition. Factory Distressed Finish. No Visible Flaws Noted. Smoke Free Home.