Windsocks are typically used at airports to show the direction and strength of the wind to pilots, and at chemical plants where there is risk of gaseous leakage.

However, some circular frame mountings cause windsocks to be held open at one end, indicating a velocity of 3 knots even when stripes are not present.

A fully extended windsock suggests a wind speed of 15 knots (28 km/h; 17 mph) or greater.

If it is necessary to use two colours, they should ideally be orange and white, arranged in five alternating bands, with the first and last darker in tone.

Wind tees are shaped like an airplane so that they match with the heading of an aircraft ready to take off and land.