Pointers mostly superfluous (7)
I believe the answer is:
needles
'pointers' is the definition.
(needle is a kind of pointer)
'mostly superfluous' is the wordplay.
'mostly' means to remove the last letter (most but not all of the word).
'superfluous' becomes 'needless' (I've seen this before).
'needless' with its last letter removed is 'NEEDLES'.
(Other definitions for needles that I've seen before include "Isle of Wight chalk monoliths" , "Christmas tree leaves" , "Teases or provokes with knitting implements" , "Sharp pointed implements" , "Isle of Wight feature - irritates" .)