Thicker gauge metal would make for sturdier construction and gives a heaviness to the cocktail shaker. While several Boston shakers are made of tin for more secure shakes, the glass rim on this Kotai shaker is tempered—the rim is heated up and cooled down for resilient glass that won’t crack https://edwininykg.thezenweb.com/helping-the-others-realize-the-advantages-of-shaker-cabinets-75633513