The 6 Heller MaxMug by Massimo Vignelli 16 oz Stackable Cup in green is a vintage set of six medium-sized mugs manufactured in the 1980s. These original and solid-color cups feature a mid-century modern design, making them suitable for all occasions and both hot and cold beverages. With a stackable feature and a capacity of 16 oz each, these mugs are perfect for teens, unisex adults, and unisex kids. Made of melamine material in the United States, the Heller MaxMug set is a collectible item that adds a touch of retro charm to any kitchen or dining area.