Abstract: A powder spray gun comrpises a tubular housing having ambient air flow passages located in the side wall thereof medially of the opposite ends. A pair of air flow amplifiers are mounted in the housing on opposite sides of the ambient air flow passages and are so oriented that compressed air supplied to the upstream one of these amplifiers, the so called suspension amplifier, is operable to draw ambient air into the outlet end of the suspension amplifier, and compressed air supplied to the downstream amplifier, the so called pattern amplifier, is operable to draw ambient air into the inlet end of the pattern amplifier. The amplifiers are secured within the housing by end caps which are sealingly secured onto the ends of the housing by bayonet pin and slot connectors.