"Riedel's newest "O" Stemless Wine Glasses are hand blown of 24% lead crystal, with two distinct impressions. To hold them, let your thumb and forefinger nestle in the niches and swirl the wine to aerate and release its aromas. With your wine glass secure, you won't smudge the beautifully clear crystal or warm up the perfectly chilled Chardonnay or properly cellared Bordeaux."