What is "glock-guitar"

A glock-guitar is a percussion instrument in the idiophone instrument family. The glock-guitar is composed of a large, flat wooden board with a smaller handle known as the akkordboard. The akkordboard usually has four round peg holes for attaching three-chime chord block sets, often making a four-note partial scale of A-minor, E, D-minor, and D. The glock-guitar can be played with several different-sized mallets or with the hand like a guitar, while the instrument is related to the glockenspiel, thus its portmanteau name in both Swedish and English.