Donated large and small hammers (6)
I believe the answer is:
gavels
'hammers' is the definition.
(I know this)
'donated large and small' is the wordplay.
'donated' becomes 'gave' (give can mean to donate).
'large' becomes 'L' (eg in clothes sizes).
'and' says to put letters next to each other.
'small' becomes 's' (abbreviation - e.g. clothes size).
'gave'+'l'+'s'='GAVELS'
(Other definitions for gavels that I've seen before include "Mallets for auctioneers" , "Mallets used by presiding officers" , "Judges' mallets" , "Auctioneers' hammers" .)