The morin khuur is a two-string fiddle about 1.15 m long, its scroll carved as a horse's head and often painted green. The soundbox is a trapezoid — roughly 20 cm across the top, 25 cm at the base, 8–9 cm deep — faced with camel, goat or sheep skin. Its two strings are bundles of horsehair: 130 stallion-tail hairs for the male string, 105 mare-tail for the female.

This system takes its structure from the object. Dark stained birch and spruce hold the ground. Pale hide and horsehair carry the reading surfaces. Cinnabar, gold and khadag blue run along edges as painted ornament, never as fill. The trapezoid governs containers; paired hairlines mark divisions; a carved terminal finishes each vertical run.