It is realized as following unrounded uvulars. A broader category is stridents, which include more fricatives such as uvulars than sibilants. Pharyngeals thus differ from uvulars, which nearly always trigger retraction. It is realized as with a central off-glide preceding both unrounded and rounded uvulars. Prototypical uvulars also appear to be [-ATR]. In the centum languages, no chain shift occurred, and the uvulars merged into the velars.