Dzus is a proprietary name for a type of quarter-turn fastener

Fastener

A fastener is a hardware device that mechanically joins or affixes two or more objects together.Fasteners can also be used to close a container such as a bag, a box, or an envelope; or they may involve keeping together the sides of an opening of flexible material, attaching a lid to a container,...

 often used to secure skin panels on aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

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It was invented and patented by a native Ukrainian William Dzus

Volodymyr Dzhus

William Dzus William Dzus William Dzus (b.1895 in Ukraine - d.1964 in New York, born Volodymyr Dzus or Dzhus (uk:Володимир Джусь) was an American engineer of Ukrainian descent, and the inventor of the Dzus fastener, also known as the quarter-turn fastener. He was also one of the founders of the...

 (Volodymyr Dzhus

Volodymyr Dzhus

William Dzus William Dzus William Dzus (b.1895 in Ukraine - d.1964 in New York, born Volodymyr Dzus or Dzhus (uk:Володимир Джусь) was an American engineer of Ukrainian descent, and the inventor of the Dzus fastener, also known as the quarter-turn fastener. He was also one of the founders of the...

) in the early 1930s. Quarter-turn fasteners are used to secure panels in equipment, airplanes, motorcycle

Motorcycle

A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...

s, and racing cars that must be removed often and/or quickly. These fasteners are notable in that they are of an "over-center" design, requiring positive sustained torque to unfasten. Thus, any minor disturbance to the fastener will correct itself rather than proceed to further loosening as it would in threaded fasteners.