An auto/manual gas inflator incorporating a gas cylinder and an auto cap. A first indication mechanism is provided for indicating the status of the gas cylinder which is visible through a first window in the inflator housing and a second indication mechanism is provided for indicating the status of the auto cap through a second window in the inflator housing. The auto cap in one embodiment uses a dissolvable pill for automatic inflation. A manual activator, such as a lanyard assembly can be used for manual inflation. In either activation method, a pierce pin is moved upward to break the cylinder's seal and release the gas contained within the cylinder.