Complex sentence: The suppressor is typically a hollow cylindrical piece of machined metal (steel, aluminium, or titanium) containing expansion chambers that attaches to the muzzle of a pistol, submachine gun or rifle.
Split into simpler sentences: The suppressor is typically a hollow metal device manufactured from (steel, aluminum, or titanium) containing expansion chambers. This device, typically cylindrical in shape, attaches to the muzzle of a pistol, submachine gun or rifle.