Abstract: An inflator for use in an airbag module assembly including a reaction canister having a stud-receiving opening in a front canister endplate and an inflator-receiving aperture in a rear canister endplate. The inflator includes an inflator housing and a mounting adaptor. The inflator housing has a generally cylindrical sidewall, a front housing end with a mounting stud extending therefrom, and a rear housing end. The mounting adaptor fits over the sidewall of the inflator housing adjacent the rear housing end and is secured to the housing by a snap engagement between a snap projection of one of the housing and the adaptor and a snap receptor of the other of the housing and the adaptor. The mounting adaptor is sized and adapted to extend through the inflator-receiving aperture of the rear canister endplate and has a radially extending flange sized and adapted to engage the rear canister endplate surrounding the inflator-receiving aperture.