They help when one is in a tearing hurry (12)

'they' is the definition.
Both the answer and definition are plural nouns.
Maybe they are linked in a way I don't understand?

'help when one is in a tearing hurry' is the wordplay.
I cannot quite see how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is found in the answer.
'one' could be 'o' (I've seen this in other clues) and 'o' is located in the answer.
'is' is present in the answer.
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is found within the answer.
The remaining letters 'frat' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

Can you help me to learn more?