Artisan Rolf of Pennsylvania handcrafts these cobalt tumblers with a school of etched fish swimming across each. Made of transition glass, produced by bottle manufacturers when switching glass colors, in this case from blue to clear. This glass, that would typically be scrapped, is repurposed into these whimsical tumblers. Dishwasher safe. Made in the USA. Set of four. Approx. 4.5'' tall, holds 14 oz.