Abstract: A hybrid inflator, includes a storage chamber for storing a pressurized gas and a pyrotechnic heater assembly which has a solid gas generating material within a combustion chamber. Forming the outer layer of the pyrotechnic heater assembly is a diffuser, which is inserted into the storage vessel. A closure provides a pressure seal between the storage chamber and the combustion chamber. Upon receiving a control signal, an igniter ignites the solid gas generating material. The closure ruptures, allowing a mixture of hot generated gas and stored gas to discharge through the diffuser and flow into a vehicle occupant restraint.