What is meant by dual-stage, multi-stage, or variable output inflation?

Dual-stage, multi-stage, or variable output are terms used to describe the operation of the air bag inflators in your air bag system that cause the air bag to fill. For dual stage or multi-stage inflators, the inflators may go off in two or more stages (steps) to tailor the amount of pressure in the frontal air bag during a crash. For a variable output inflator, the inflator can tailor the output across a range of inflation pressures.

In general, for less severe crashes requiring less inflation force, only one stage of a dual-stage/multi-stage inflator may go off, or there may be less output pressure from a variable output inflator. Both result in a lower-pressure air bag deployment. For more severe crashes, all stages of a dual-stage/multi-stage inflator may go off at the same time or there may be full output from a variable output inflator. Both result in a higher-pressure air bag deployment.