A multi-rotor drone can be available in a wide variety of drive configurations. The most common models have at least four drive motors, half of which run clockwise and the other half anti-clockwise. This arrangement is called a quadrocopter. If the drone has six motors, it is known as a hexacopter and can have three or six booms. Three booms are referred to as a coaxial arrangement, as one left and one right-rotating motor is installed per boom. A hexacopter is generally used when larger loads need to be carried, but also when safety requirements demand that the system be controlled in the event of a motor failure. This is referred to as drive redundancy. An octocopter, either with four or eight booms, can also compensate for several failed motors, depending on the design of the system. Exotic arrangements such as dodecacopters (12 drives), which have maximum redundancy and a high load-bearing capacity, are also used for cinema production cameras.