The A flat augmented seventh chord is a 4-note chord consisting of the notes Ab, C, E and G.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Abmaj7#5.
Interactive piano diagram for the A flat augmented seventh chord
Chords that are a subset of Abmaj7#5. These contain less notes but all of them are included in Abmaj7#5.