guitar chord
A♯sus4
The third replaced by the fourth, which leans on the third it is standing in for.
Written the other way round it is B♭sus4 — the same twelve keys on a piano, a different piece of notation.
Every fingering that fits a hand
668866
moderate · barre
x11341
moderate · barre
688866
hard · barre
66886x
moderate · barre
x1334x
hard
What is true of it
A♯sus4 is A♯, D♯ and E♯ — 1, 4 and 5 counted from A♯.
These are also the notes of D♯sus2/A♯ and E♭sus2/A♯. Which name is right depends on what is underneath and what came before — the notes alone do not decide.
The easiest of the 5 fingerings below is 668866: 3 fingers, one of them barring the 6th fret, held at the 6th fret.
None of them uses an open string, so this chord moves up the neck unchanged — the same shape 1 fret higher is the chord a semitone above.
4 of the 5 need a barre.
Where its notes are on the neck
The brass dots are A♯, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
A♯sus4/D♯
x68866
A♯sus4/E♯
111341
An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.