The Savoy knot, a type of decorative knot

Knot

A knot is a method of fastening or securing linear material such as rope by tying or interweaving. It may consist of a length of one or several segments of rope, string, webbing, twine, strap, or even chain interwoven such that the line can bind to itself or to some other object—the "load"...

, is a heraldic knot

Heraldic knot

A heraldic knot is a knot, unknot, or design incorporating a knot used in European heraldry. While a given knot can be used on more than one family's achievement of arms, the family on whose coat the knot originated usually gives its name to the said knot...

 used primarily in Italian heraldry. It is most notable for its appearance on the heraldic badge of the House of Savoy

House of Savoy

The House of Savoy was formed in the early 11th century in the historical Savoy region. Through gradual expansion, it grew from ruling a small county in that region to eventually rule the Kingdom of Italy from 1861 until the end of World War II, king of Croatia and King of Armenia...

, where it is accompanied by the motto

Motto

A motto is a phrase meant to formally summarize the general motivation or intention of a social group or organization. A motto may be in any language, but Latin is the most used. The local language is usual in the mottoes of governments...

 Stringe ma non costringe, "It tightens, but does not constrain". In shape, it is comparable to a figure eight.

When used outside of heraldry (as a real knot), it is known as a figure-eight knot.

The Savoy knot can also be seen on the Alfa Romeo automobile badge (which is basically the emblem of the city of Milan, Italy.)