You can push your hand right through it (6)
I believe the answer is:
sleeve
'hand right through it' is the definition.
I know that 'hand' relates to this answer.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for sleeve that I've seen before include "It's attached to the armhole" , "Part of a garment covering the arm" , "Cover for a gramophone record" , "with something to hide?" , "Garment's arm" .)