The standard grips this chord is usually shown with.
F#sus2sus4 is F#, G#, B and C#, a suspended second and fourth. The shape this page opens on is written 224424, lowest string first.
Note by note. F# is the root, G# is the ninth, B is the fourth and C# is the fifth.

Also written F#sus2/4 or F# suspended 2nd and 4th. The same chord either way; which spelling you meet depends on who wrote the chart.
There are 4 common shapes for F#sus2sus4 on the guitar, and 21 derived voicings in 2 families.
One note away. Change a single note of F#sus2sus4 and you have F#sus2 (with one note taken away), F#sus4 (with one note taken away), F#add9 (with one note moved), F#madd9 (with one note moved), F#7sus4 (with one note moved) or F#11 (with one note added).
In which keys. Every note of F#sus2sus4 belongs to C# minor (the iv), Eb minor (the ♭III), E major (the ii), F# major (the I), F# minor (the i), Ab minor (the ♭VII), A major (the vi) and B major (the V).
The common shapes, written lowest string first: 224424, x96677, x-9-9-11-9-9, 14-14-11-13-x-x.
Under the hand. None of the shapes for F#sus2sus4 uses an open string, so every one of them is movable; the lowest sits at the 2nd fret. 2 of the 4 need a barre. Together they cover the neck from the 2nd fret to the 14th.
Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. F#sus2sus4 has xx4424, 4444xx, xx6677, x-x-9-11-9-9, 9-11-9-11-x-x, x-11-11-11-12-x, x2412x, x4647x.
Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. F#sus2sus4 has x2x122, 4x442x, x4x474, 7x667x, x9x697, x-11-x-11-12-9, 9-x-9-11-9-x, 14-x-11-13-12-x.
What kind of chord this is. F#sus2sus4 is a suspended chord — root and fifth, with a second or fourth where the third would be — or nothing at all. suspended and power chords on every root, and what they are for.
The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.