Cyclonic air treatment member and surface cleaning apparatus including the same

A vacuum cleaner comprising an air flow path extending from a dirty air inlet to a clean air outlet with a first cyclonic cleaning stage and a suction motor positioned in the air flow path, the first cyclonic cleaning stage comprising a first cyclone chamber and a first dirt collection chamber external to the first cyclone chamber, the first cyclone chamber having a cyclone first end, an opposed cyclone second end, a cyclone sidewall extending between the cyclone first end and the cyclone second end, a cyclone air inlet, a cyclone air outlet provided at the cyclone second end, a cyclone dirt outlet in communication with the first dirt collection chamber and a cyclone longitudinal axis extending from the cyclone first end to the cyclone second end, wherein the dirt outlet comprises a plurality of apertures, wherein the cyclone air outlet extends inwardly a first distance from the cyclone second end towards the cyclone first end, and wherein the cyclone sidewall extends angularly 360° around the cyclone longitudinal axis and a portion of the cyclone sidewall having the plurality of apertures extends angularly only part way around the cyclone longitudinal axis and wherein the portion of the sidewall extends inwardly into the cyclone chamber a distance that is up to about the first distance.