Open shape
x0101x
Am7♭5 is the A half-diminished chord. Its notes are A, C, E♭ and G. Also written ø7. Often the ii chord in a minor ii–V–i progression.
x0101x
Numbers show frets from the low E string to the high e string; x means don't play that string.
Am7♭5 is the viiø7 chord in B♭ major. That makes it a natural fit in songs written in those keys.
Every A, C, E♭ and G on the first 12 frets. The filled dots are the root, A. Build your own shape from any nearby group.
Other A chords
Other half-diminished chords