Double summit eroded. Triple peaks occur more rarely - one example is the Rosengartenspitze in the Dolomites. The Illimani in Bolivia is an example of a quadruple summit. Well known double summits are (roughly from east to west): Double summit A double summit, double peak, twin summit or twin peak refers to a mountain or hill that has two summits, separated by a col or saddle. One well known double summit is Austria’s highest mountain, the Großglockner, where the main summit of the Großglockner is separated from that of the Kleinglockner by the Glocknerscharte col in the area of a geological fault.
Quadruple reed Quadruple reed A quadruple reed is a type of reed by means of which the sound is originated in various wind instruments. The term "quadruple reed" comes from the fact that there are four pieces of dried palm leaf vibrating against each other, in pairs. A quadruple reed, such as the Thai pinai, operates in a similar way as the double reed and produces a timbre similar to the oboe. The Arabic "pii chawaa" is, "sometimes described as having a double reed though this is actually folded yet again, creating four layers of reed and thus requiring considerable lung power